The researchers assigned the rats to four groups: a control group, a cyclophosphamide-plus-saline group, a saline-plus-B. clausii group, and a cyclophosphamide-plus-B. clausii group. Immunosuppression and intestinal mucositis were induced through intraperitoneal administration of cyclophosphamide, followed by oral B. clausii treatment. The abstract reports that clinical findings, hematological measurements, intestinal histopathology, histomorphometry, cytokine levels, and miR-146a expression were evaluated.

Cyclophosphamide alone was associated with villus shortening, epithelial disruption, inflammatory infiltration, fibrosis, and depletion of goblet cells. Compared with controls, rats receiving cyclophosphamide alone had 10.58% shorter villi and 44.20% fewer goblet cells, with both differences reported as P < 0.001. In the cyclophosphamide-plus-B. clausii group, villus length increased by 17.81% and goblet-cell count by 66.34% relative to the cyclophosphamide-plus-saline group, also with P < 0.001 for both comparisons. B. clausii treatment attenuated the cyclophosphamide-associated increases in the pro-inflammatory cytokines TNF-α and IL-6.

The findings support a partial protective effect within this rat model, rather than evidence of a clinical benefit in people receiving chemotherapy. miR-146a expression remained reduced in both cyclophosphamide-treated groups, and the abstract states that the mechanisms behind the observed protective effects remain unclear. The authors also identify effects on miR-146a, the intestinal microbiota, inflammatory pathways, and intestinal barrier function as subjects for further research. Because the experiment involved 32 male rats and assessed an intervention after experimentally induced injury, it cannot establish efficacy, dosing, safety, or benefit in human patients. The available evidence therefore supports continued mechanistic and clinical investigation, but not clinical recommendations.

Subject of Research: Effects of oral Bacillus clausii on cyclophosphamide-induced intestinal injury in rats

Article Title: Protective effects of Bacillus clausii in cyclophosphamide-induced immunosuppression and intestinal mucositis in rats: histopathological and inflammatory evaluation

Article References: Ekinci, G., Daldaban, F., Tüfekçi, E., Yıldız, G., Balcıoğlu, E., Akyüz, B., Güneş, V., & Arslan, K. (2026). Protective effects of Bacillus clausii in cyclophosphamide-induced immunosuppression and intestinal mucositis in rats: histopathological and inflammatory evaluation. Molecular Biology Reports, 53(1), Article 1588. https://doi.org/10.1007/s11033-026-12773-z

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12773-z

Keywords: Bacillus clausii, cyclophosphamide, intestinal mucositis, immunosuppression, rat experiment, goblet cells, intestinal inflammation, TNF-α, IL-6, miR-146a, Protective, effects

Sarcopenia is one of the most consequential and least well understood consequences of aging. As muscle fibers shrink and mitochondria, the cell’s energy factories, falter, older adults lose the strength to climb stairs, carry groceries or recover from illness, and their risk of falls, frailty and metabolic disease climbs sharply. While adult lifestyle factors such as inactivity and poor diet are known contributors, the question of whether nutrition in the earliest window of life can set the trajectory of muscle aging has remained largely unexplored. The new findings suggest it can.

The team used mouse models in which pups were overfed during the neonatal period, a developmental stage in rodents that corresponds broadly to infancy in humans. Litter sizes were manipulated so that some pups received more milk than others during suckling, creating a controlled form of early overnutrition. The animals were then followed into old age. Compared with normally fed controls, the overfed mice had shorter lifespans, worse late-life muscle atrophy and clear metabolic dysfunction, including disturbances in glucose handling. Crucially, the effect appeared in both sexes, indicating that the developmental programming was not a sex-specific quirk.

The mechanistic heart of the study lies in the gut. Neonatal overfeeding, the researchers found, disrupts the development of goblet cells, the specialized epithelial cells that secrete the protective mucus layer lining the intestine. This layer is far more than passive lubrication. It forms a physical barrier that separates the dense microbial community of the gut from the underlying immune tissue, and its composition, particularly its supply of mucin glycans, determines which microbes can thrive there. When goblet cell development goes awry, the mucus barrier remains defective for life, and the consequences ripple outward across the lifespan.

One microbe proved especially sensitive to this altered environment: Akkermansia muciniphila, a well-known mucus-dwelling bacterium that has attracted intense interest for its associations with metabolic health. In the overfed mice, the persistent mucus barrier defects led to reduced colonization by A. muciniphila as the animals aged. The loss was not merely a correlate. When the researchers performed fecal microbiota transplantation, transferring gut microbes from overfed, sarcopenic mice into recipient animals, the sarcopenic phenotype came along with the microbes, directly implicating gut dysbiosis in the propagation of the muscle-wasting disease.

Why would the disappearance of a single gut bacterium weaken skeletal muscle? The answer appears to run through a short-chain fatty acid called acetate. A. muciniphila is a producer of acetate, a metabolite that circulates systemically and signals to host tissues through receptors including GPR43, also known as FFAR2, a G-protein-coupled receptor expressed in tissues including muscle and immune cells. In the mice lacking A. muciniphila, acetate production dropped, GPR43 signaling was suppressed, and muscle mitochondria suffered. Mitochondrial function in the aged muscle was impaired, meaning the fibers could not efficiently generate the energy required to maintain their mass and contractile performance. The result was aggravated sarcopenia.

The most striking part of the study is that the damage proved reversible, at least in aged mice. When the researchers reconstituted A. muciniphila, either by giving the bacterium directly or by supplementing acetate, mitochondrial homeostasis in the muscle was restored and physical performance improved. This rescue experiment closes the causal loop: it shows not only that the loss of the microbe accompanies muscle decline but that restoring the microbe or its key metabolite can meaningfully improve muscle function late in life. It also identifies acetate signaling through GPR43 as a concrete molecular target linking gut ecology to mitochondrial health in skeletal muscle.

The broader significance of the work is its reframing of sarcopenia as a disease with developmental origins. The concept of the developmental origins of health and disease holds that nutritional and environmental exposures during critical windows of early development can permanently shape physiology and disease risk decades later. Most research in this area has focused on cardiovascular and metabolic outcomes. This study extends the paradigm to the musculoskeletal system and supplies a mechanistic pathway: early overnutrition reprograms gut mucosal development, which reshapes the microbiota, which in turn alters metabolite availability and mitochondrial function in muscle across the lifespan. The gut-muscle axis, as the authors describe it, becomes a conduit through which an infantile dietary excess is converted into an aged, weakened body.

There are important caveats. The findings come from mice, and the neonatal overfeeding model, while well established, involves litter-size manipulation that does not map perfectly onto human infant feeding practices. Human infancy involves a different developmental timeline, different milk composition and a far more variable nutritional environment. Whether overfeeding during human infancy accelerates muscle aging through an analogous goblet cell and A. muciniphila pathway remains an open question that will require long-term human cohort studies. The authors themselves frame the work as revealing a developmental origin of age-related sarcopenia and defining a gut-muscle axis, rather than as a demonstration of a clinical intervention.

Even so, the preventive implications are considerable. If early-life overnutrition leaves a lifelong imprint on the gut barrier and microbiota, then optimizing infant nutrition could be a form of preventive medicine for healthy aging, protecting not only against childhood obesity and adult metabolic disease but against the frailty of old age. The rescue experiments point to a second, complementary possibility: that A. muciniphila or acetate-based interventions might one day help preserve muscle function in people already aging with an unfavorable microbial legacy. As populations worldwide grow older and sarcopenia imposes mounting costs on health systems, the idea that the seeds of late-life muscle decline are planted in the first weeks of life, and that they may be weeded out through the gut, is a finding likely to reshape how researchers think about aging, nutrition and the microbes that live along for the ride.

Subject of Research: How neonatal overfeeding programs lifelong gut mucosa and microbiota changes that accelerate age-related sarcopenia in mice

Article Title: Neonatal overfeeding accelerates age-related sarcopenia and metabolic disorders through lifelong gut mucosa and microbiota programming in mice

Article References: Song, Y., Xu, J., Zhao, J., Yang, R., Ma, Y., Hou, Y.-M., Cao, Y., Li, J., Yu, S., Liang, X., Zhang, Y., Wang, K., An, L., Liu, Y., Meng, Z.-X., Fan, J.-G., & Xie, C. (2026). Neonatal overfeeding accelerates age-related sarcopenia and metabolic disorders through lifelong gut mucosa and microbiota programming in mice. Nature Communications. https://doi.org/10.1038/s41467-026-78216-2

Image Credits: AI Generated

DOI: 10.1038/s41467-026-78216-2

Keywords: sarcopenia, neonatal overfeeding, gut microbiota, Akkermansia muciniphila, goblet cells, mucus barrier, acetate, GPR43, mitochondria, muscle aging, developmental origins, metabolic disorders

Astroviruses are small, non-enveloped RNA viruses that infect the small intestine, where they cause gastroenteritis that can be particularly severe in young children, the elderly, and immunocompromised patients. Despite their clinical importance, fundamental aspects of the astrovirus replication cycle have remained poorly resolved, including the deceptively simple question of how newly assembled viral particles leave the cells that produce them. The research team, led by Natalie Pedicino and colleagues, reasoned that the answer might lie in a distinctive feature of astrovirus tropism: these viruses preferentially infect goblet cells, the specialized epithelial cells of the intestinal lining whose entire existence is organized around the production and secretion of mucus.

Goblet cells are the mucus factories of the gut. They synthesize enormous quantities of mucins, the heavily glycosylated proteins that give mucus its gel-like protective properties, and store them in membrane-bound secretory granules packed within the cytoplasm. When appropriately stimulated, goblet cells undergo regulated exocytosis, fusing these granules with the plasma membrane and expelling their mucin cargo into the intestinal lumen. This process, known as mucus secretion, is a fundamental component of intestinal barrier function, and it is driven in large part by intracellular calcium signals that trigger granule fusion. Because astroviruses infect precisely the cells that perform this function, the researchers hypothesized that the viruses might have evolved to exploit the secretory pathway itself, packaging themselves into the same cellular cargo that goblet cells are built to release.

To test this hypothesis, the team turned to the murine astrovirus model, a well-established experimental system that permits the study of astrovirus infection in its natural intestinal context. Examining infected intestinal tissue, the researchers made a striking observation: the release of virus from infected cells co-occurred almost exclusively with episodes of mucus secretion from goblet cells. Wherever virus was being shed, mucus was being expelled, and the two events appeared to be tightly coupled rather than merely coincidental. This spatial and temporal association suggested that viral egress was not an independent process but was physically and mechanistically linked to the secretory activity of the infected goblet cells.

The correlation extended beyond individual cells to the level of the whole tissue. When the researchers tracked infection kinetics over time, they found that mucus secretion rates rose and fell in parallel with viral load. As the infection progressed and the immune system began to clear the virus, mucus secretion returned toward baseline levels, mirroring the decline in viral shedding. This coordinated pattern reinforced the idea that the secretory state of the tissue and the propagation of the virus were intimately connected throughout the course of infection, not just at a single snapshot in time.

Correlation alone, however, cannot establish causation, so the researchers next manipulated mucus secretion directly and asked what happened to viral release. When they disrupted mucin biosynthesis, thereby impairing the goblet cells’ ability to produce and package their mucus cargo, viral shedding from infected tissue was reduced. Conversely, when they stimulated mucus secretion pharmacologically using carbachol, a drug that activates muscarinic receptors and triggers the calcium-dependent secretory pathway, viral release increased. The bidirectional nature of this effect, in which dampening secretion reduced virus release and enhancing secretion boosted it, provided strong functional evidence that the mucus secretory pathway is not merely a passive correlate of infection but an active route of viral egress.

To determine whether this mechanism extends to human astroviruses, which are clinically the most relevant, the team needed an appropriate cell culture system. They established a new infection model using LS174T cells, a human cell line derived from a colonic adenocarcinoma that retains goblet-cell-like properties, including the capacity to produce and secrete the major intestinal mucin MUC2. In these infected goblet-like cells, the researchers observed that human astrovirus particles colocalized with MUC2 within the cell, suggesting that the virus and the mucin cargo occupy the same intracellular compartments during the secretory process. The association was further confirmed using purified mucin granules, with viral particles found in association with the isolated granules themselves.

The pharmacological experiments in the human cell model recapitulated and extended the findings from the murine system. Stimulating LS174T cells with carbachol enhanced the release of both mucus and virus, and this dual effect could be blocked by the addition of a muscarinic receptor antagonist, which prevents the receptor-mediated activation of the secretory pathway. The researchers also probed the intracellular signal that drives granule exocytosis: calcium. When they blocked intracellular calcium signaling, the trigger that normally causes mucin granules to fuse with the plasma membrane, virus release was reduced. Together, these experiments traced the egress pathway from receptor activation through calcium signaling to granule exocytosis, showing that human astrovirus exploits each step of the canonical mucus secretion machinery.

The significance of these findings lies in what they reveal about both the astrovirus replication cycle and the broader biology of non-enveloped enteric viruses. Egress is the step of the viral life cycle that determines how efficiently a virus spreads from cell to cell and, ultimately, from host to host. By demonstrating that astroviruses use mucus secretion as a non-lytic form of egress, the study resolves a longstanding gap in understanding how these viruses complete their replication cycle. It also suggests a possible explanation for aspects of astrovirus pathogenesis: a virus that exits the cell by hitching a ride on mucus is delivered directly into the luminal mucus layer of the intestine, positioning itself for transmission while potentially modulating the barrier and immune functions of the mucus itself. The tight coupling between viral shedding and secretory activity may therefore have consequences that extend beyond viral spread to the diarrhea and intestinal dysfunction that characterize astrovirus disease.

More broadly, the work adds mucus secretion to the repertoire of host pathways that non-enveloped viruses can commandeer for exit, joining mechanisms such as extracellular vesicle release and cell-to-cell spread that have been described for other enteric pathogens. It also highlights the value of studying viruses in the context of the specific cell types they naturally infect. The connection between astroviruses and goblet cells was the key insight that made this discovery possible, and it serves as a reminder that viral strategies are often best understood not in generic cell culture systems but in the specialized cellular environments where infection actually occurs. As researchers continue to probe how this novel egress pathway shapes astrovirus transmission and disease, the findings open new avenues for therapeutic intervention, since drugs or interventions that modulate mucus secretion could, in principle, influence viral shedding and the course of infection.

Subject of Research: Non-lytic egress of astroviruses through mucus secretion from intestinal goblet cells

Article Title: Astroviruses use mucus secretion as a novel form of viral egress

Article References: Pedicino, N., Kirkpatrick, M. G., Pablo, M. A., Gulman, J., Heredia-Osuna, N., & Cortez, V. (2026). Astroviruses use mucus secretion as a novel form of viral egress. PLOS Pathogens, 22(10), e1014683. https://doi.org/10.1371/journal.ppat.1014683

Image Credits: AI Generated

DOI: 10.1371/journal.ppat.1014683

Keywords: astrovirus, viral egress, goblet cells, mucus secretion, MUC2, mucin granules, pediatric diarrhea, non-enveloped viruses, calcium signaling, carbachol, LS174T cells, murine astrovirus

The answer, according to the study, is no. In a chicken embryo model of early-life intestinal stress, whole Rubired grape pomace, a grape seed extract, and a grape skin and pulp food coloring each protected the gut in distinct and only partially overlapping ways. The finding matters because the food industry has largely moved away from whole pomace, which consumers accept poorly, toward derivative products such as grape seed extracts and natural food colorings. If the original byproduct and its derivatives are not functionally interchangeable, then upcycling strategies that assume equivalence may be leaving nutritional value on the table—or, conversely, may be concentrating specific benefits in ways the whole material cannot match.

To test this, the researchers turned to a well-established in ovo approach. Chicken embryos develop rapidly and independently inside the egg, which makes them a powerful platform for studying early-life intestinal biology without the confounding variables of maternal influence or post-hatch diet. The team induced intestinal stress using dextran sulfate sodium, or DSS, a chemical that damages the intestinal epithelial barrier and is widely used to model inflammatory stress in the gut. DSS injures the single layer of cells lining the intestine, disrupting the delicate architecture of villi and crypts that the gut depends on for absorption and renewal. Into this stressed environment, the researchers introduced three Rubired (Vitis vinifera) preparations: the whole pomace (RGP), the seed extract (RSEED), and the skin and pulp food coloring (RCOLOR), each evaluated for its capacity to blunt the damage.

The clearest and most consistent result concerned the small intestine. DSS exposure depleted the surface area of the duodenal villi—the finger-like projections that dramatically expand the absorptive surface of the gut—and reduced both the density and the size of goblet cells, the specialized epithelial cells that secrete mucus and form a first line of defense against luminal threats. Remarkably, all three grape preparations restored these losses. Whether delivered as whole pomace, concentrated seed extract, or natural coloring, the grape-derived material helped the embryonic duodenum rebuild its villus architecture and replenish its mucus-producing cell population. This suggests that the core protective activity against small-intestinal damage is broadly shared across the grape byproduct family, likely reflecting phenolic compounds that persist in every fraction of the fruit.

The colon told a more selective story. Here, DSS triggered crypt hyperplasia—an abnormal proliferation of the invaginated glands that house the gut’s stem cell niche—yet only two of the three preparations countered it. The grape seed extract and the skin and pulp food coloring attenuated colonic crypt hyperplasia, while the whole pomace did not. This split is scientifically significant because it indicates that the compounds responsible for protecting the colonic crypt compartment are not evenly distributed across the grape. The seed and the skin and pulp fractions appear to concentrate bioactivity that the whole pomace, with its different composition and perhaps lower effective doses of key phenolics, could not deliver in this model.

At the molecular level, the picture shifted again. The researchers examined zonula occludens-2, or ZO2, a tight junction protein that helps seal the gaps between adjacent epithelial cells and maintain the integrity of the intestinal barrier. DSS exposure dysregulated duodenal ZO2, and here it was the whole pomace and the food coloring—not the seed extract—that restored normal regulation. Tight junction proteins are central to barrier function; when they falter, the gut becomes permeable to antigens and microbes, fueling inflammation. The fact that RGP and RCOLOR normalized ZO2 while RSEED did not demonstrates that the seed extract, despite its colonic benefits, left a gap in barrier-level protection in the duodenum.

The microbiome added yet another dimension of divergence. Only the grape seed extract recovered the relative abundance of Clostridium, a bacterial genus with important roles in the gut ecosystem, including the production of short-chain fatty acids that nourish colonocytes and support immune development. Neither the whole pomace nor the food coloring achieved this microbial recovery. In other words, each of the three grape products excelled at a different facet of intestinal resilience: all three repaired small-intestinal structure, two of three protected colonic crypts, two of three restored tight junction regulation, and only one reshaped the microbiota in the measured direction. No single preparation dominated across every endpoint.

These results carry real implications for how the food industry approaches upcycling. If grape seed extracts and natural colorings are marketed as functional equivalents of the pomace they come from, the new data suggest that assumption is too simple. The bioactivity of grape byproducts is fraction-dependent: processing decisions that concentrate certain phenolics inevitably redistribute others. For product developers, this means the choice between whole pomace, seed extract, and skin-derived coloring is not merely a matter of consumer acceptance or cost—it is a choice about which biological targets, from villus architecture to tight junction integrity to microbial balance, a given ingredient can realistically support. Conversely, the study strengthens the case for pomace itself as a reservoir of value, since it matched or exceeded its derivatives on several endpoints despite being the least refined material.

The study also highlights the value of early-life models. The embryonic and neonatal gut undergoes rapid maturation, and insults during this window can have lasting consequences for barrier function, immune programming, and microbial colonization. By showing that grape-derived phenolics can counteract DSS-induced stress at this vulnerable stage, the Cornell team adds to a growing body of evidence that maternal and early-life nutrition can be leveraged to support gut health from the very beginning of development. The chicken embryo model, with its speed and controllability, allowed the researchers to compare three products side by side across structural, molecular, and microbial endpoints within a single experimental framework.

The authors are careful about the limits of their work. The findings were generated in an avian embryonic model, and the study itself notes that future research in mammalian models and across extended early-life periods is needed to establish translational relevance and mechanistic context. Chicken embryo intestines differ from mammalian ones in ways that could alter how phenolic compounds are absorbed, metabolized, and delivered to target tissues, and the DSS challenge in ovo is a proxy for inflammatory stress rather than a specific human disease. Still, the central conclusion stands on firm ground within its model: grape byproducts hold genuine potential to mitigate early-life intestinal stress, but they do so in distinct ways. As the pressure to halve global food waste intensifies, the humble pile of pressed grapes left behind after each harvest may prove to be not a liability but a differentiated portfolio of bioactive ingredients—provided that science, not assumption, guides which fraction goes where.

Subject of Research: Effects of grape pomace, seed extract, and skin/pulp food coloring on DSS-induced early-life intestinal stress in a chicken embryo model

Article Title: Comparing the bioactivity of grape byproducts (pomace, seed extract, and skin/pulp food coloring) on DSS-induced intestinal stress in early life

Article References: Huang, M. Y., & Tako, E. (2026). Comparing the bioactivity of grape byproducts (pomace, seed extract, and skin/pulp food coloring) on DSS-induced intestinal stress in early life. npj Science of Food. https://doi.org/10.1038/s41538-026-01148-0

Image Credits: AI Generated

DOI: 10.1038/s41538-026-01148-0

Keywords: grape pomace, food waste, upcycling, phenolic compounds, intestinal barrier, dextran sulfate sodium, chicken embryo model, goblet cells, tight junctions, ZO2, gut microbiota, early-life nutrition

The research team, led by scientists at the Southern Marine Science and Engineering Guangdong Laboratory in Zhanjiang, compared four feeding strategies over a 21-day trial in juvenile croakers: normal daytime feeding, intermittent fasting with two days of feeding followed by one day without food, continuous fasting, and nighttime feeding. Each group was reared under identical conditions — 30-degree water, 27 parts per thousand salinity, and a standardized commercial diet offered at 2 percent of total biomass when feeding occurred. Afterward, the researchers dissected the fish’s intestines for histological examination, sequenced the gut microbiome using 16S rRNA gene sequencing, and profiled gene expression across the intestinal transcriptome.

The morphological results were striking. Fish subjected to continuous fasting showed markedly shortened intestinal villi — the finger-like projections that expand the absorptive surface of the gut — along with a sharp loss of goblet cells, the mucus-secreting cells that form a critical chemical barrier against pathogens. In contrast, intermittently fasted fish developed the tallest villi of any group, suggesting adaptive mucosal hyperplasia that maximizes nutrient uptake when food returns. This compensatory remodeling echoes patterns seen in Nile tilapia and even in mammalian models of fasting-refeeding, and it represents an evolutionarily conserved strategy for recovering from periods of scarcity.

Beneath the tissue level, the microbial ecosystem told its own story. Continuous fasting disrupted microbial homeostasis, enriching genera with troubling reputations: Vibrio, a well-documented destroyer of intestinal epithelium and driver of inflammation; Actinomyces, linked to metabolic disorders and inflammatory responses; Photobacterium, repeatedly associated with compromised health in stressed aquatic animals; and Akkermansia. The daytime-fed control group, by comparison, maintained higher relative abundances of Firmicutes and Bacteroidota — phyla central to digestive efficiency and immune balance — while keeping Proteobacteria in check. Linear discriminant analysis effect size, or LEfSe, further revealed that intermittent fasting enriched beneficial taxa including Parabacteroides and Bilophila, while continuous fasting preferentially boosted Flavonifractor.

The transcriptomic analysis added a molecular dimension to these observations. Continuous fasting triggered a broad transcriptional reprogramming, suppressing genes central to energy metabolism — pfkfb4, a master regulator of the glycolysis-lactate axis, and pla2g12b, involved in phospholipid metabolism — while downregulating rptor, a key component of the mTORC1 signaling pathway that governs epithelial renewal, and pecam1, an immune-related gene. Meanwhile, col1a, a collagen gene tied to structural integrity, was upregulated, likely reflecting tissue stress and repair responses. Quantitative reverse-transcription PCR confirmed these expression patterns across ten key genes, lending robustness to the sequencing data.

Intermittently fasted fish, by contrast, sustained healthy expression of the genes governing energy metabolism and barrier function. Rather than undergoing wholesale transcriptional reprogramming, these animals appeared to adapt primarily through their microbiota: the intermittently fasted group showed the highest microbial diversity and the most complex co-occurrence network among gut bacteria. The authors suggest this microbial stabilization fosters mucosal protection through ecological competition — beneficial communities crowding out potential pathogens — a mechanism that is metabolically cheaper for the host than constant genetic adjustment.

To tie these threads together, the team constructed a partial least squares path model integrating intestinal morphology, gene expression, microbial composition, serum biochemistry, and growth performance. The model, which showed good overall fit, revealed a clear cascade: gut microbiota significantly influenced host gene expression, gene expression shaped intestinal phenotype, and intestinal architecture — villus height and goblet cell density above all — emerged as the strongest direct positive driver of weight gain rate. Serum glucose, cortisol, and lactate, meanwhile, exerted a significant negative effect on growth. Microbes, in other words, do not determine growth directly; they act upstream, tuning the genetic programs that build the gut, which in turn sets the pace of growth.

Nighttime feeding produced a subtler picture. Compared with daytime feeding, the nocturnal schedule elicited only minor downregulation of energy metabolism genes and modest changes in muscularis thickness, without significant morphological damage or microbial disruption. This suggests that, over the three-week window of the experiment, circadian misalignment alone imposes limited costs on this species — a finding that contrasts with studies in species whose natural rhythms align more tightly with night feeding, such as darkbarbel catfish and Dabry’s sturgeon, where nocturnal schedules improved nutrient utilization.

The practical implications for aquaculture are considerable. Feed represents one of the largest operating costs in fish farming, and intermittent feeding schedules have already been shown to cut costs while preserving health in species like longfin yellowtail and neotropical catfish, and to trigger compensatory growth in Nile tilapia and Siberian sturgeon. This study adds a mechanistic foundation to that empirical record: the two-day feeding, one-day fasting cycle sustained villus height, goblet cell density, and microbial diversity simultaneously, positioning it as a promising protocol for Nibea coibor specifically. The findings also carry a warning — prolonged fasting, whether for cost savings or pre-slaughter management, risks metabolic depression, barrier dysfunction, and blooms of potentially pathogenic bacteria that could undermine both welfare and yield.

Beyond the fish farm, the work contributes to a growing appreciation of gut microbiota as a metabolic interface between diet and host physiology. By demonstrating that microbial communities can regulate intestinal architecture through host transcription — and that this cascade ultimately governs growth — the study provides a systemic framework that could guide feeding optimization across marine aquaculture. As the authors note, the intestine sits at the crossroads of absorption and microbial ecology, and it is precisely there that the economics of feeding schedules are converted into the biology of growth. For an industry under pressure to produce more protein with fewer resources, understanding that conversion may prove one of the most valuable tools available.

Subject of Research: Effects of feeding strategies on intestinal morphology, transcriptome, and microbiota in farmed Nibea coibor

Article Title: Integrated transcriptomic and microbiota analyses reveal growth-related intestinal responses to feeding strategies in Nibea coibor

Article References: Qu, Z., Zhou, J., Li, R., Min, Q., Yi, X., Zhuang, Z., Yuan, B., Ba, X., Zhao, N., & Zhang, B. (2025). Integrated transcriptomic and microbiota analyses reveal growth-related intestinal responses to feeding strategies in Nibea coibor. Advanced Biotechnology, 3(4), Article 37. https://doi.org/10.1007/s44307-025-00088-2

Image Credits: AI Generated

DOI: 10.1007/s44307-025-00088-2

Keywords: Nibea coibor, aquaculture, feeding strategies, intermittent fasting, gut microbiota, intestinal homeostasis, transcriptomics, 16S rRNA sequencing, goblet cells, villus height, PLS-PM, fish growth

The study was designed to address a glaring gap in the microplastics literature. Although microplastics have been confirmed in human tissues, including the liver, intestines, and even the placenta, most toxicological investigations have relied on in vitro cell cultures or single-sex animal cohorts, leaving regulators with limited information about how whole organisms respond to realistic, repeated exposure. The Health Canada team chose C57BL/6 mice, one of the most thoroughly characterized laboratory strains, and divided animals by sex to capture biological variation that shorter or single-sex studies routinely miss. Crucially, they also compared two particle geometries: uniform commercial spheres, which dominate the literature because they are easy to characterize, and milled particles with jagged, irregular edges, which more closely resemble the fragmented plastics found in food, water, and air.

Animals received the particles by daily oral gavage for 28 consecutive days, a duration that in regulatory toxicology is classified as a subacute exposure window, long enough for effects to emerge in rapidly dividing tissues such as the gut lining, but short enough to isolate direct toxicity from age-related changes. The researchers then assembled an unusually comprehensive assessment battery. They tracked food consumption and body weight throughout the exposure, weighed organs at necropsy, ran complete hematology panels, measured a broad suite of clinical biochemistry markers reflecting liver and kidney function, profiled both innate and adaptive immune cell populations by flow cytometry, quantified pro-inflammatory cytokines, and examined tissues histologically under the microscope. Raman spectroscopy was used to hunt for plastic particles in collected tissues, confirming whether the material actually crossed from the gut lumen into the body.

The first surprise was how quiet the systemic picture looked. Across all treatment groups, there were no significant changes in food consumption, body weight, or relative organ weights. Hematological parameters, including red and white blood cell counts, remained within normal ranges, and clinical biochemistry markers of organ function showed no statistically meaningful disturbances. For anyone who has followed alarmist headlines about microplastics, the results might seem anticlimactic. But the team emphasizes that the absence of classical systemic toxicity endpoints does not mean the exposure was biologically inert. Subtle changes were quietly accumulating in tissues that routine blood panels cannot see, and those changes were distributed unevenly between the sexes.

The most dramatic finding emerged in the gallbladder. Histological examination revealed gallbladder inflammation in 9 of 23 male mice exposed to the particles, compared with only 2 of 24 exposed females, a skew so pronounced that it is unlikely to be chance. The inflammatory lesions appeared in animals exposed to both spherical and milled particles, suggesting that particle chemistry rather than precise geometry drove the response in this organ. The gallbladder is not a tissue that has featured prominently in microplastics research, which has focused overwhelmingly on the intestine, liver, and lungs, and the finding raises immediate questions about biliary health in chronically exposed animals and, by extension, humans. Whether the inflammation reflects direct physical contact by particles transiting the biliary tract, a secondary response to altered bile composition, or an immune-mediated process remains unresolved.

Male mice also showed a second, subtler immune signature: pro-inflammatory cytokines were decreased across all polystyrene-exposed male groups. A drop in inflammatory signaling molecules might superficially sound beneficial, but in immunology, dampened cytokine output can indicate immune dysregulation, a blunting of the normal responsiveness that animals need to fight infections and clear damaged tissue. The adaptive and innate immune cell populations measured by flow cytometry showed no major shifts, which makes the cytokine suppression even more intriguing, because it suggests a functional change in cell behavior rather than a change in cell numbers. The authors note that this pattern was specific to males; females did not display the same systemic cytokine profile.

Female mice told a completely different story, one written in the tissue of the small intestine. Instead of gallbladder inflammation, exposed females developed mild pathological changes in the intestinal lining, most notably alterations in the goblet cell population and in mucus production. Goblet cells are the gut’s dedicated mucus factories, secreting the protective gel layer that lubricates the intestinal surface and forms a critical barrier against bacteria, dietary antigens, and foreign particles. Changes in goblet cell abundance or mucus output are therefore not cosmetic; they can alter gut permeability, shift the microbiome, and modulate how the intestine tolerates everything from food proteins to pathogens. Because the intestine is the first point of contact for ingested microplastics, these findings suggest that in females, the primary biological conversation between plastic and body happens at the gut barrier itself.

Raman analysis added a crucial piece of evidence: polystyrene was detected in both the liver and the intestines of animals of both sexes. This confirms that at least a fraction of the ingested particles crossed or associated with the intestinal epithelium and reached the liver, the body’s central detoxification organ. Particle translocation is a key variable in the risk assessment of nano- and microplastics, because systemic distribution opens the door to effects far beyond the gut. The detection of plastic in liver tissue after only 28 days of exposure demonstrates that the mammalian body does not simply pass these materials through as inert cargo.

Just as important as the sex differences was what did not differ: spherical and milled particles produced broadly similar toxicological results. This is a consequential observation for the field, because much of the existing microplastics literature relies on idealized spheres for experimental convenience. If milled, irregular fragments, which better approximate environmental weathered plastic, behave like spheres in vivo, then laboratory findings using spherical particles may be more transferable to real-world risk than critics have assumed. At the same time, the authors are careful to frame the geometry question as far from settled, and the gallbladder findings appeared across both particle types in this study.

The broader takeaway is a call for sex as a standard variable in microplastics toxicology. Regulatory toxicity testing has only in recent decades moved toward requiring both sexes in study design, and the microplastics field, much of it built on expedient single-sex models, has lagged behind. The Health Canada results demonstrate that pooling or ignoring sex can mask biologically meaningful signals, from suppressed cytokine responses in males to gut barrier remodeling in females. The study was funded by the Government of Canada’s Advancing a Circular Plastics Economy Initiative, reflecting a policy landscape in which plastic production continues to accelerate globally while the health consequences of chronic, low-level human exposure remain only partially mapped. As humans continue to ingest and inhale plastic particles daily, research of this kind provides the granular, sex-disaggregated, mechanism-oriented data that will ultimately determine whether microplastics represent a quiet hazard, an active threat, or something in between.

Subject of Research: Sex-specific toxicological effects of oral polystyrene nano- and microplastic exposure in mice

Article Title: Sex-specific toxicological observations following 28-day oral gavage exposure to spherical and milled polystyrene nano- and microplastic particles in mice

Article References: Marcellus, K. A., Scur, M., Abdulmawjood, S., Wang, G. S., Mason, C., Singh, G., & Gill, S. S. (2026). Sex-specific toxicological observations following 28-day oral gavage exposure to spherical and milled polystyrene nano- and microplastic particles in mice. Microplastics and Nanoplastics. https://doi.org/10.1186/s43591-026-00226-0

Image Credits: AI Generated

DOI: 10.1186/s43591-026-00226-0

Keywords: microplastics, nanoplastics, polystyrene, toxicology, mice, sex differences, gallbladder inflammation, small intestine, goblet cells, cytokines, oral gavage, Health Canada