Search Results (607)

Herbivorous animals rely on complex gastrointestinal systems and microbial communities to efficiently digest plant-based diets, extract nutrients, and maintain health. Recent advances in metagenomic technologies have enabled high-resolution, culture-independent analysis of gut microbiota composition, functional potential, and host–microbe interactions, providing insights into microbial diversity across the herbivore digestive tract. This review summarizes key findings on the gastrointestinal microbiota of herbivores, focusing on ruminant foregut and non-ruminant hindgut fermentation. Ruminants like cattle, sheep, and goats host microbiota enriched with fibrolytic and methanogenic microbes that facilitate fiber degradation and volatile fatty acid production, contributing significantly to energy balance. In contrast, non-ruminants such as horses and rabbits rely on hindgut fermentation, with distinct microbial taxa contributing to carbohydrate and protein breakdown. The review further explores how specific microbial taxa, including Prevotella, Fibrobacter, and Ruminococcus, correlate with improved feed efficiency and growth performance, particularly in ruminants. Additionally, the roles of probiotics, prebiotics, and symbiotics in modulating gut microbial composition and enhancing productivity are discussed. Despite significant advances, challenges remain in microbial sampling, functional annotation, and understanding the integration of microbiota with host physiology. The review emphasizes the potential of metagenomic insights in optimizing herbivore gut microbiota to improve feed efficiency, health, and sustainable livestock production. Full article

This study evaluated the effects of dietary potassium diformate supplementation on growth performance, nutrient digestibility, gastrointestinal pH, jejunal morphology, digestive enzyme activity, and antioxidant status of weaned piglets in a 28-day trial. Twenty-four weaned piglets were selected and, after a 4-day adaptation period, randomly assigned to 4 treatment groups (n = 6). The dietary treatments included a control diet (basal diet) and 3 diets supplemented with 0.6%, 1.2%, or 1.8% potassium diformate in the basal diet. The results indicated that the feed conversion ratio (FCR) of piglets was reduced by all three potassium diformate supplementation levels compared to the control group (p < 0.05). Additionally, the FCR was decreased in piglets fed the 1.8% potassium diformate-supplemented diet compared to those fed the 1.2% potassium diformate-supplemented diet (p < 0.05). Piglets fed the three potassium diformate-supplemented diets exhibited higher apparent total tract digestibility (ATTD) of dry matter and crude protein than the control group (p < 0.05). The 1.8% potassium diformate groups also showed increased ATTD of calcium and phosphorus compared to the control group (p < 0.05). Supplementation with 1.2% or 1.8% potassium diformate reduced the digesta pH in the proximal stomach, distal stomach, and duodenum, while increased jejunal villus height (VH), VH/crypt depth (VH/CD) ratio, and catalase and total superoxide dismutase activities in the jejunal mucosa compared to the control group (p < 0.05). The 1.2% potassium diformate group showed higher α-amylase activity than the control group (p < 0.05). Correlation analysis revealed that FCR negatively correlated with ATTD of dry matter, crude protein, calcium, phosphorus, and jejunal VH, while positively correlating with digesta pH in the proximal stomach (p < 0.05). The ATTD of dry matter negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum, and positively correlated with jejunal VH/CD ratio and catalase activity (p < 0.05). The ATTD of crude protein negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum (p < 0.05). Collectively, dietary supplementation with 1.8% potassium diformate reduced FCR of weaned piglets, which was associated with enhanced nutrient digestibility, reduced pH in the anterior gastrointestinal tract, and improved jejunal morphology. Full article

Social communication difficulties characterize autism spectrum disorders (ASD). Gastrointestinal (GI) symptoms are more common in ASD than in the general population. The identification of GI problems in individuals with ASD is challenging due to their altered pain perception and irregular behaviors. Importantly, GI symptoms and ASD can potentially aggravate each other. However, it is unclear if GI problems cause ASD symptoms or vice versa. A crosstalk between the digestive system, gut microbiota, and the central and enteric nervous systems (CNS and ENS, respectively) has been repeatedly reported. The ENS regulates the GI tract with the CNS and the autonomic nervous system (ANS), as well as independently through specific neural circuits. Several mechanisms contribute to GI problems in ASD, including genetic mutations that affect the ENS, dysregulation of the ANS, alterations in gut microbiota, unhealthy dietary preferences, and changes in metabolomic profiles. Furthermore, studies have shown molecular and cellular differences in the GI biopsy of children with and without ASD. These findings highlight the unique nature of GI issues in ASD, underscoring the importance of further investigating the changes that occur in the digestive system and ENS in ASD models. Full article

The gastrointestinal (GI) tract is increasingly recognized as an important regulator of energy balance and metabolism, extending beyond its traditional digestive functions. This review synthesizes current research on how modifications to the GI tract, particularly those induced by metabolic bariatric surgery (MBS), influence hormonal and physiological processes involved in glucose regulation and appetite control. MBS procedures, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), induce significant and sustained weight loss, but also elicit adaptive morphological and functional changes within the intestines. These alterations include intestinal hypertrophy, increased mucosal surface area, changes in nutrient transit time, and modifications in enzyme activity. Such changes enhance the secretion of key gut hormones, including glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), which play vital roles in promoting insulin secretion, suppressing appetite, and improving blood glucose regulation. The benefits stem from the exposure of undigested nutrients to different intestinal segments, which stimulates enteroendocrine activity and positively influences systemic metabolism. These hormonal adaptations contribute significantly to the metabolic improvements observed post-surgery, independent of weight loss alone. Understanding how gut structural and functional changes drive hormonal responses provides valuable insights into the mechanisms underlying the success of MBS. Moreover, elucidating these processes may facilitate the development of less invasive therapies that mimic the metabolic benefits of surgery. Ultimately, this research advances our understanding of gut-mediated regulation of energy and glucose homeostasis and holds promise for improving treatment strategies for obesity and related metabolic disorders. Full article

The undesirable properties of bioactive substances (such as poor solubility and low stability) and various barriers in the gastrointestinal tract (gastric acid, digestive enzymes, mucus and intestinal epithelial cells) hinder their absorption and utilisation by the human body. Nanodelivery systems have been proven to effectively address the above problems, particularly targeted nanodelivery systems, which have more advantages in improving the bioavailability of bioactive substances. However, many studies have not included all barriers. Furthermore, given that the small intestine is the main site for the absorption of bioactive substances in the human body, this review primarily discusses targeted nanodelivery systems designed for the gastrointestinal barrier and summarises how to construct a nanodelivery system that can resist the adverse effects of the gastrointestinal tract and target the small intestine for the absorption of bioactive substances. This paper proposes that the ideal system is the active targeted nanodelivery system that targets enterocytes and its future development trend is discussed. This review aims to provide new insights for the rational design of nanodelivery platforms that efficiently target the small intestine and promote the absorption of bioactive substances, as well as promote the development of fields such as personalised nutrition and nutritional intervention. Full article

Background/Objectives: The probiotic Lacticaseibacillus paracasei DG (LpDG) has shown promising results for various gastrointestinal diseases. This study evaluated the survival, metabolic activity, and impact on colonic microbiota of LpDG in an in vitro gastrointestinal tract simulation. Methods: Encapsulated LpDG was tested under simulated fed, fasted, and shortened fasted conditions compared with a blank control in a modified Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®) reactor. Capsule integrity, and cell culturability and viability were assessed at the end of each digestion phase. Metabolic activity (pH, total gas production, and concentrations of short-chain fatty acids, lactate, and ammonium) was assessed after a 24 h colonic incubation with a faecal inoculum. The impact of LpDG on the colonic microbial community was analysed by quantitative polymerase chain reaction and shallow shotgun sequencing. Results: The capsule was completely degraded at the end of the jejunum under all conditions. A low pH had a minimal impact on LpDG culturability and viability. Compared with blank control, LpDG remained metabolically active in the microbial community following a 24 h colonic incubation (LpDG [0–24 h] vs. blank control [0–24 h]: ΔpH, decreased [0.29–0.38 vs. 0.12–0.34]; Δlactic acid, decreased [1.52–1.69 mM vs. 0.13–0.21 mM]; and Δbutyrate, increased [7.49–10.52 mM vs. 5.19–7.76 mM]). Under fed conditions, treatment with LpDG compared with blank control significantly decreased levels of Escherichia coli and Blautia wexlerae and increased Clostridiaceae, Eubacteriaceae, and Lachnospiraceae. Conclusions: LpDG remains viable and metabolically active in the gastrointestinal tract, positively affecting intestinal microbiota and metabolite production. Full article

Encapsulation of fish oil within oleogels can potentially prevent oxidation and enable its use in food with programmable release within the gastrointestinal tract. Here, we report on the formation of oleogels from two different fish oils—salmon oil (SO) and cod liver oil (CLO)—using different concentrations of either rice bran wax (RBW) or myristic acid (MA) as gelators. The gels were assessed with respect to their structural, thermal, viscosity, digestive, and oxidative properties. Polarized light microscopy (POM) revealed that RBW consistently produced dense, interconnected crystalline networks across both oils, while MA formed larger, spherulitic crystals that were more sensitive to the oil type. This was further supported by time-lapse imaging, showing faster crystal growth of MA in cod liver oil. Viscosity studies indicate that the molecular weight and concentration of gelator, as well as the type of fish oil (SO vs. CLO), significantly impact the shear stability of the oleogels. Thermal and viscosity analyses confirmed that RBW-based oleogels exhibited higher crystallization temperatures and stronger viscoelastic behaviour. Based on oxidative stability measurements—as measured by peroxide value (PV) analysis—encapsulation within oleogels does not lead to significant oxidation of the fish oils and also attenuates further oxidation upon storage. The fish oil oleogels were stable when exposed to either simulated gastric or intestinal fluids (SGF and SIF, respectively), but decomposed after sequential exposure first to SGF and then to SIF. These findings could broaden the range of food products which can be fortified with fish oils. Full article

The human gastrointestinal tract hosts a complex ecosystem known as the gut microbiota, which plays a crucial part in digestion and immune system function. Among the clinically recognized manifestations of dysbiosis in this system are Small Intestinal Bacterial Overgrowth (SIBO), Intestinal Methanogen Overgrowth (IMO), Small Intestinal Fungal Overgrowth (SIFO), and Large Intestinal Bacterial Overgrowth (LIBO). This study aims to investigate the complex pathophysiological mechanisms underlying these syndromes and their diagnostics and therapeutic options, focusing primarily on the roles of methane-producing archaea and fungal overgrowth. The methods employed in this study involve a comprehensive analysis and synthesis of peer-reviewed articles, systematic reviews, clinical trials, and meta-analyses. This review summarizes that methane production by Methanobrevibacter smithii was linked to altered fermentation, reduced microbial diversity, and slowed intestinal transit. Fungal species were associated with increased intestinal permeability, inflammation, and biofilm formation. Targeted interventions addressing microbial imbalances demonstrated potential therapeutic value. This review highlights the complex and multifactorial nature of gut dysbiosis, revealing its impact beyond the gastrointestinal tract. While emerging therapies targeting methanogens, fungi, and biofilms show promise, further research is essential to optimize their clinical application. The findings emphasize the need for interdisciplinary collaboration to refine diagnostic and therapeutic strategies. Full article

This review highlights the anti-hyperglycemic and antidiabetic properties of camel and dromedary milk (CM). Diabetes mellitus poses a significant global health challenge, and strategies that reduce reliance on insulin or other medications could substantially improve patient management. CM could represent a promising complementary approach due to its established antidiabetic effects, which are supported by its unique biological characteristics. Compared to other common milks, such as bovine milk, CM contains higher concentrations of insulin. Its distinctive physicochemical and microstructural properties help protect insulin and other bioactive proteins from degradation in the gastrointestinal tract, thereby enhancing their intestinal absorption. Furthermore, peptides generated during CM protein digestion may exert direct or indirect effects on the liver and pancreas, contributing to improved glucose metabolism. These beneficial actions are further supported by CM’s antioxidant and antilipidemic properties, which may help mitigate diabetes-related complications, including renal dysfunction and skin lesions. Full article

The healthy properties of a functional food not only depend on its content in bioactive compounds—such as curcumin—but also on the changes that it undergoes during the digestive process that affect its bioaccessibility and bioavailability. This research aims to study oral in vitro bioaccessibility and bioavailability as key design variables for the rational design of three novel delivery systems (oleogel vs. Og/W simple emulsion vs. W₁/Og/W₂ multiple emulsion) with the dual purpose of facilitating the transport and controlled release of curcumin and simultaneously encapsulating and safeguarding the carried lipid phase (ω-3 PUFAs) against oxidation processes (the latter was previously optimized). To this end, a dynamic in vitro simulating system (SimuGIT) was used to mimic the release and absorption mechanisms throughout the gastrointestinal tract, including the oral (2 min), gastric (30 min) and intestinal phases (180 min). The oleogelified (not emulsified) system turned out to be the least bioaccessible and bioavailable, although the most promising strategy in terms of efficiency once released, with 41.8 ± 1.8% of the bioaccessible curcumin after the digestion phase being bioavailable at the end of the gastrointestinal tract. On the other hand, both emulsified systems, Og/W and W₁/Og/W₂, showed similar final bioavailability up to the colonic simulated stage of around 20.2 ± 2.5%, 1.7 times higher than that of the oleogel (p < 0.05) and 2.5 greater as compared to other in vitro values reported in the literature for free curcumin. Surprisingly, the curcumin in the W₁/Og/W₂ multiple emulsion was absorbed faster than the one vectorized in the Og/W system; thus, in terms of net values, both Og/W and W₁/Og/W₂ emulsions provided the same bioavailable curcumin. However, in terms of controlled release, the multiple emulsion would be the most suitable encapsulation system for rapid delivery, and the single emulsion for longer-term release applications. Thus, information obtained from this study could be useful in designing functional foods for the controlled delivery of lipophilic bioactive compounds. Full article

Chlorophyll, the green pigment essential for photosynthesis, abundantly found in green vegetables and algae, has attracted growing scientific interest for its potential therapeutic effects, particularly in diabetes management. Recent research highlighted that chlorophyll and its derivatives may beneficially influence glucose metabolism and oxidative stress, key factors in diabetes. This review examines current knowledge on how chlorophyll compounds could aid diabetes control. Chlorophyll and its derivatives appear to support glucose regulation primarily through actions in the gastrointestinal tract. They modulate gut microbiota, improve glucose tolerance, reduce inflammation, and alleviate obesity-related markers. While chlorophyll itself does not directly inhibit digestive enzymes like α-glucosidase, its derivatives such as pheophorbide a, pheophytin a, and pyropheophytin a may slow carbohydrate digestion, acting as α-amylase and α-glucosidase inhibitors, reducing postprandial glucose spikes. Additionally, chlorophyll enhances resistant starch content, further controlling glucose absorption. Beyond digestion, chlorophyll derivatives show promise in inhibiting glycation processes, improving insulin sensitivity through nuclear receptor modulation, and lowering oxidative stress. However, some compounds pose risks due to photosensitizing effects and toxicity, warranting careful consideration. Chlorophyllin, a stable semi-synthetic derivative, also shows potential in improving glucose and lipid metabolism. Notably, pheophorbide a demonstrates insulin-mimetic activity by stimulating glucose uptake via glucose transporters, offering a novel therapeutic avenue. Overall, the antioxidant, anti-inflammatory, and insulin-mimicking properties of chlorophyll derivatives suggest a multifaceted approach to diabetes management. While promising, these findings require further clinical validation to establish effective therapeutic applications. Full article

Type 2 diabetes mellitus (T2DM) is a multifactorial disorder defined by insulin resistance, β-cell dysfunction, and chronic hyperglycemia. Although peripheral mechanisms have been extensively studied, increasing evidence implicates the gastrointestinal tract in disease onset. Insights from bariatric surgery, gut hormone signaling, and incretin-based therapies suggest that the gut contributes actively beyond nutrient absorption. Yet, a cohesive framework integrating these observations remains absent, leaving a critical gap in our understanding of T2DM’s upstream pathophysiology. This work builds upon the anti-incretin theory, which posits that nutrient-stimulated neurohormonal signals—termed “anti-incretins”—arise from the proximal intestine to counteract incretin effects and regulate glycemic homeostasis. The excess of anti-incretin signals, perhaps stimulated by macronutrient composition or chemical additives of modern diets, disrupts this balance and may cause insulin resistance and β-cell depletion, leading to T2D. We hypothesize that the neuroendocrine signals produced by cholecystokinin (CCK)-I and secretin-S cells, both located in the proximal intestine, function as endogenous anti-incretins. In this context, we hypothesize a novel model centered on the chronic overstimulation of I and S cells by high-fat, high glycemic index modern diets. This drives what we term “amplified digestion”—a state marked by heightened vagal and hormonal stimulation of biliary and pancreatic secretions, increased enzymatic and bile acid activity, and alterations in bile acid composition. This condition leads to an extended breakdown of carbohydrates, lipids, and proteins into absorbable units, thereby promoting excessive nutrient absorption and ultimately contributing to insulin resistance and progressive β-cell failure. Multiple lines of clinical, surgical, and experimental evidence converge to support our model, rooted in the physiology of digestion and absorption. Western dietary patterns appear to induce an over-digestive adaptation—marked by excessive vagal and hormonal stimulation of biliary and pancreatic secretion—which amplifies digestive signaling. This heightened state correlates with increased nutrient absorption, insulin resistance, and β-cell dysfunction. Interventions that disrupt this maladaptive signaling—such as truncal vagotomy combined with duodenal bypass—may offer novel, physiology-based strategies for T2DM treatment. This hypothesis outlines a potential upstream contributor to insulin resistance and T2DM, grounded in digestive tract-derived neurohormonal dysregulation. This gut-centered model may provide insight into early, potentially reversible stages of the disease and identify a conceptual therapeutic target. Nonetheless, both the hypothesis and the accompanying surgical strategy—truncal vagotomy combined with proximal intestinal bypass—remain highly exploratory and require systematic validation through mechanistic and clinical studies. Further investigation is warranted to clarify the molecular regulation of I and S enteroendocrine cells, including the genetic and epigenetic factors that may drive hypersecretion. While speculative, interventions—surgical or pharmacologic—designed to modulate these digestive signals could represent a future avenue for research into T2DM prevention or remission, pending rigorous evidence. Full article

Phenols are natural compounds with considerable bioactivities. However, the low bioavailability and chemical instability of phenols limit their biological functions. This review summarizes recent progress in phenol delivery systems that account for the specific physiological conditions of the gastrointestinal tract. It focuses on the delivery materials for intestinal targeting and the synergistic benefits of co-encapsulating phenols with other functional ingredients. To achieve targeted release of phenols in the digestive tract, factors such as pH, digestive enzymes, and gut microbiota should be fully considered in delivery system designing. Materials like chitosan, sodium alginate, pectin, and guar gum offer effective protection and targeted delivery of phenols due to their pH sensitivity and enzyme-degradable properties. Co-delivery systems that combine phenols with carotenoids or probiotics improve the functional properties of phenols, such as antioxidant activity, anti-inflammatory effect, and regulation of gut microbiota. Probiotics can enhance phenolic compound absorption and probiotic survival in a phenolic–probiotic co-encapsulation system through debonding, bioconversion, and synergistic effects. Full article

Gastrointestinal (GI) involvement is frequent in systemic sclerosis (SSc). Recent studies have highlighted a possible association between GI symptoms, gut microbiota (GM), and nutrition. In this systematic review, the evidence supporting these relationships was evaluated. Articles selected from the MEDLINE database and published between 2010 and 2025 were included. Keywords used in the sources included “systemic sclerosis”, “gut microbiota”, “malnutrition”, and “gastrointestinal symptoms”. Forty-nine articles were selected, for a total of 6270 SSc patients. The evidence suggests a complex relationship between SSc, GI symptoms, and GM dysbiosis. Both are manifestations of the disease, and in turn they influence its severity. Digestive tract fibrosis and dysbiosis alter nutrient absorption, which can lead to malnutrition. However, data considering these complex relationships between the GI tract, microbiome, and nutritional status are few and very heterogeneous. Further studies are needed to investigate these complex interwinings and identify nutritional interventions able to reduce GI dysfunction and simultaneously counteract malnutrition. Full article

In vitro cartilage explant culture has been used to assess nutraceuticals on cartilage responses to inflammatory stimuli. However, applying extracts of nutraceuticals directly to cartilage explants does not account for effects of digestion and hepatic biotransformation, or selective exclusion of product metabolites from joint fluid by the synovial membrane. The current study produced a simulated biological extract of a common nutraceutical (glucosamine; G_sim) by exposing it to a simulated upper gastrointestinal tract digestion, hepatic biotransformation by liver microsomes, and purification to a molecular weight cut-off of 50 kDa. This extract was then used to condition cartilage explants cultured for 120 h in the presence or absence of an inflammatory stimulus (lipopolysaccharide). Media samples were analyzed for prostaglandin E₂ (PGE₂), glycosaminoglycan (GAG), and nitric oxide (NO). Tissue was digested and analyzed for GAG content and stained for viability. Conditioning of explants with G_sim significantly reduced media GAG in stimulated and unstimulated explants and reduced nitric oxide production in unstimulated explants. These data provide evidence for the value of glucosamine in protecting cartilage from deterioration following an inflammatory challenge, and the model improves applicability of these in vitro data to the in vivo setting. Full article