The Role of Gut Microbiota in Human Nutrition and Health: A Mini Review Volume 62- Issue 2

Haunmant Singh Rathore*

• Associate Professor, Department of Biotechnology, SET, Nagaland University, India

Received: May 21, 2025; Published: June 02, 2025

*Corresponding author: Haunmant Singh Rathore, Associate Professor, Department of Biotechnology, SET, Nagaland University, Kohima Campus, Meriema-797004, India

DOI: 10.26717/BJSTR.2025.62.009702

Abstract PDF

Comprising trillions of microorganisms living in the human gastrointestinal tract, the dynamic and complex ecosystem known as gut microbiota is absolutely essential for maintaining host nutrition, metabolic homeostasis, and immune function. Dysbiosis, or disturbances in the gut microbial balance, is linked to a wide spectrum of health problems including obesity, type 2 diabetes, inflammatory bowel disease, and even neurological diseases. This mini review highlights present knowledge of how the gut microbiota affects nutrient metabolism, immune system modulation, and interaction with dietary components to either promote or compromise health. Future therapeutic and nutritional plans could be customised to restore and preserve a healthy gut microbial ecosystem given mounting proof connecting diet to microbiome composition.

Research on the human microbiome has revealed during the last ten years the significant influence of the gut microbiota on almost every aspect of human physiology. Home to over 100 trillion microbial cells-mostly bacteria-the gut outnumbers human cells by a factor of 10 and has more than 100 times the number of genes than the human genome. Among their many vital tasks, these bacteria ferment undigested dietary components, create vitamins, control gut barrier function, and affect the immune system. Many elements, including genetics, mode of birth delivery, antibiotic exposure, and especially diet, shape the composition and activity of the gut microbiota. Diet is one of the most changeable elements, thus knowing its interaction with the microbiota provides useful information on how to enhance health results by means of nutrition.

Microbiota and Nutrient Metabolism

By breaking down complicated carbohydrates and proteins that elude enzymatic digestion in the small intestine, gut bacteria improve human digestion. Among these are dietary fibers and resistant starchs, which bacteria in the colon ferment to generate short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. Colonic epithelial cells’ main energy source is butyrate, which also helps to preserve intestinal barrier integrity. The liver absorbs propionate and helps to produce glucose. The most prevalent SCFA, acetate, affects lipid metabolism and appetite control by entering systemic circulation. Gut bacteria also produce necessary vitamins including: Involved in bone metabolism and blood clotting, vitamin K2 Crucial for energy generation and neurological function are B vitamins-e.g., B12, biotin, folate. These metabolic interactions suggest that the microbiota is an extension of the human digestive system, therefore allowing the host to draw more energy and nutrients from food.

Diet as a Microbial Composition Modulator

Microbiota composition and diversity are mostly influenced by diet. While suppressing the growth of pathogenic bacteria, a fiber-rich, plant-based diet helps to promote the growth of good commensals like Bifidobacterium, Faecalibacterium prausnitzii, and Lactobacillus. On the other hand, Western-style diets heavy in fat, sugar, and animal proteins are linked to lower microbial diversity and higher amounts of Firmicutes and Proteobacteria, which have been connected to inflammation and obesity.Inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS) among other prebiotics-non-digestible fibers that selectively nourish good bacteria-can boost SCFA synthesis and help immune function. When taken often, probiotics-live good bacteria in fermented foods like yogurt, kefir, and sauerkraut-can help to restore microbial balance. The gut flora also metabolizes polyphenols from fruits, tea, and chocolate into bioactive chemicals with anti-inflammatory and antioxidant properties. Interventional studies highlight the flexibility of the gut ecosystem and its response to nutritional inputs by demonstrating that even small dietary changes can produce notable changes in microbiota composition.

Microbiota–Immune System Interactions

Both the innate and adaptive immune systems are shaped mainly by the gut microbiota. From early life, bacteria teach the immune system to differentiate between benign antigens and dangerous pathogens. Commensal bacteria support gut mucosal immunity maintenance, increase anti-inflammatory cytokines (likeIL-10) production, and promote the growth of regulatory T-cells.

Dysbiosis has been connected to: Diseases of the immune system- e.g., rheumatoid arthritis, type 1 diabetes, Diseases of inflammatory bowel, such as Crohn’s disease and ulcerative colitis, Allergies and asthma, particularly when early life microbial exposure is restricted (hygiene hypothesis). By encouraging the integrity of the gut barrier and restricting the movement of inflammatory endotoxins (e.g., lipopolysaccharides) into the circulation, SCFAs-especially butyrate- also affect immune reactions.

Health and Disease Management Implications

Restoring microbial balance by means of dietary and lifestyle changes offers hope for controlling several chronic diseases. Plans are as follows: Nutrition programs tailored to microbiome profiles. Supplementation with synbiotic (prebiotics+ probiotics) or probiotic. In instances of severe dysbiosis-for example, recurrent Clostridioides difficile infection-fecal microbiota transplantation (FMT). With microbial metabolites affecting mood, cognition, and behaviour, emerging studies also connect the microbiota-gut-brain axis to mental health. This paves the way for fresh psychobiotic treatments aimed at neurodegenerative diseases, anxiety, and depression [1-5].

A crucial, flexible component of human physiology is the gut microbiota. Diet is a strong modulator of microbial health; thus, nutritional plans that improve microbial diversity and function are probably going to have notable effects on public health. Ongoing study on diet-microbiota-host interactions will help to create focused treatments for individualized nutrition and disease prevention.

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