MNRDC’s Bio-foundry workshop – unveil the core science behind SCFAs, Gut Health and Chronic Disease. Learn how Acetate, Propionate, & Butyrate regulate immunity, protect cells from oxidative damage, influence cognition, & link microbiome health to chronic disease across inflammatory bowel disease, diabetes and cardiovascular disease.

Let’s come to the fact: fibre is medicine, and that’s simply not a fancy metaphor. When fibre hits the colon, the bacteria eventually ferment it. And what comes out is called Short Chain Fatty Acis as known as SCFA, of two, three or a maximum of four carbons. The shocking part is that nobody in the pharmaceutical domain, the entire research would look twice at molecules, this small. Since that’s a mistake, these tiny things regulate immune functionality, protect DNA from carcinogens, and signal the brain. Followed by sitting at the centre of research into 8 chronic diseases.

This draws on Dr Anupam Jyoti ‘s session at Parul University’s April 2026 MNRDC workshop on microbial cells as green bio-foundries . He is an associate professor & CRO (Chief Research Officer) at the Faculty of Applied Sciences. He did his PhD from CSIR, also known as the Central Drug Research Institute, in Lucknow. The deep-dive session has the experimental data. This is the wider biology, in plain terms.

Three molecules. Acetate, two carbons. Propionate, three. Butyrate, four. Acetate is what sours vinegar. Butyrate is the smell of rancid butter. Nobody designed these; they come out of fermentation in the colon every time fiber arrives there, get absorbed into the blood, and start behaving as signals to organs nowhere near the gut. Acetate feeds lipid metabolism and tells the brain when to stop eating. Propionate works on liver function and glucose regulation, which is the link to type 2 diabetes research. Butyrate is the primary fuel for the cells lining the colon and carries the strongest anti-inflammatory and cytoprotective punch of the three. On the clinical front, it has been watched mostly!

Two routes are running at the same time. That is the whole explanation for why SCFAs appear across so many different immune research contexts.

The first route is receptor binding. SCFAs attach to G-protein coupled receptors (GPCRs), the seven-pass transmembrane proteins found on cell surfaces. When the right SCFA binds to the appropriate GPCR on an immune cell, it triggers an intracellular signalling cascade that can reshape cytokine production, influence regulatory T-cell differentiation, and modify B-cell activity. At the surface level, this functions much like many other receptor-mediated signalling events.

The second route is slower but more fundamental: histone deacetylase (HDAC) inhibition. Inside the nucleus, DNA wraps around histone proteins, and the tightness of this winding determines which genes are accessible to the transcription machinery. Acetyl groups loosen the DNA-histone interaction, while histone deacetylases remove these groups, tightening the structure. SCFAs inhibit histone deacetylases, helping maintain a more open chromatin structure so that immune-related genes remain accessible for transcription. Unlike GPCR signalling, this mechanism produces longer-lasting effects because it influences gene accessibility rather than only activating short-term signalling pathways.

Together, these two routes explain how molecules produced in the colon can influence immune function throughout the body. When dietary fibre intake remains high, the gut microbiome continues producing SCFAs, helping maintain this regulatory balance. When fibre intake declines or the microbiome becomes disrupted, SCFA production falls, this regulatory system weakens, and immune dysregulation may follow.

Cells are constantly exposed to environmental stressors. These include ultraviolet (UV) radiation, ionising radiation, temperature extremes, airborne particulate matter, xenobiotics, industrial contaminants, and microbial toxins. Pathogens such as Salmonella and certain pathogenic Escherichia coli (E. coli) strains can also produce toxic metabolites that place additional stress on cells.

Although these stressors originate from different sources, they often produce the same outcome: the generation of reactive oxygen species (ROS). These highly reactive molecules contain an unpaired electron and readily react with nearby cellular components, including proteins, amino acids, lipids, and DNA. Such reactions cause oxidative damage that can impair normal cellular function.

Oxidative stress may damage DNA, trigger programmed cell death (apoptosis), and alter protein structure and function through oxidative modification. Over time, persistent oxidative stress has been associated with skin ageing, wrinkles, hyperpigmentation, tissue inflammation, and the development of several chronic diseases.

Two important transcription factors help regulate the cellular response to oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) activates antioxidant and detoxification genes after moving from the cytoplasm into the nucleus. However, prolonged oxidative stress can interfere with this process, reducing the cell’s protective response. In contrast, nuclear factor kappa B (NF-κB) is activated during cellular stress and promotes the expression of genes involved in inflammation and apoptosis. The balance between Nrf2 activation and NF-κB signalling plays an important role in determining whether cells maintain protection or enter a pro-inflammatory state.

Short-chain fatty acids (SCFAs) have been shown to support Nrf2 activity while suppressing NF-κB signalling. Experimental studies involving compounds such as pyrogallol and p-coumaric acid, discussed during Dr. Anupam Jyoti’s session, demonstrate similar regulatory mechanisms in cultured cells exposed to carcinogens and UV radiation. These findings suggest that microbial metabolites may help maintain cellular antioxidant defences and reduce inflammatory responses under conditions of oxidative stress.

Dysbiosis is the collapse of the balance between beneficial and harmful gut bacteria. Antibiotics cause it directly. A low-fibre, processed-food diet starves the SCFA-producing bacteria. Chronic stress shifts both gut motility and bacterial makeup. Contaminated food imports species that crowd out the good ones. Once the balance is lost, harmful bacteria stop being kept in check. Toxic metabolites replace useful ones. The gut wall inflames, the barrier weakens, and inflammatory signals leak into the bloodstream.

A decade ago, nobody would have connected the following diseases to gut microbes. Inflammatory bowel disease came first, the ulcerative colitis and Crohn’s disease connection was the most obvious and the earliest recognised. Type 2 diabetes followed, glucose signalling and systemic inflammation now settled parts of its picture. Rheumatoid arthritis keeps looking more dysbiosis-shaped. Pulmonary fibrosis belongs to a gut-lung axis still being unpicked. Cardiovascular disease connects through SCFA effects on lipids and vascular inflammation. Non-alcoholic fatty liver disease is common across India now, with obesity riding alongside it as a lifestyle factor, a point Dr Anupam Jyoti made directly in the workshop. Obesity ties back to satiety signalling. Several cancers now show microbial-metabolite involvement in how immune cells monitor tumours. None of this makes the microbiome the lone cause. It makes restoring SCFA production, through fiber, fermented foods, or engineered probiotics, a serious clinical research priority.

The gut and the brain communicate through a two-way network known as the gut-brain axis, and short-chain fatty acids (SCFAs) play an important role in this communication.

One pathway is neural. Signals generated in the gut travel through the vagus nerve to brain regions involved in regulating mood, appetite, stress responses, and other physiological functions.

The second pathway is biochemical. After being produced by the gut microbiome, SCFAs are absorbed into the bloodstream. Some can cross the blood-brain barrier, where they influence neuroinflammation, neurotransmitter activity, and gene expression within brain cells.

Diet strongly influences the composition of the gut microbiome, which in turn affects SCFA production. Through both neural and biochemical pathways, SCFAs may influence brain function, including mood, cognitive performance, learning, memory, and attention. These findings highlight the close relationship between nutrition, gut microbial activity, and brain health.

Short-chain fatty acids (SCFAs) are among the most extensively studied microbial metabolites, but they represent only one group of bioactive compounds produced by the gut microbiome. Other microbial products, including bacteriocins and exopolysaccharides (EPS), are also receiving increasing attention for their potential therapeutic applications.

Bacteriocins are antimicrobial proteins or peptides produced by bacteria to inhibit or eliminate competing bacterial strains. Within microbial communities, they function as natural defence molecules. Research has also shown that certain bacteriocins can influence host immune responses. For example, sublancin has been reported to enhance the phagocytic activity of macrophages, the immune cells responsible for engulfing and destroying pathogens. Similarly, nisin has been shown to promote the formation of neutrophil extracellular traps (NETs), structures composed of chromatin and antimicrobial proteins that help trap and eliminate pathogens outside immune cells. Experimental studies, including scanning electron microscopy, have visualised these immune responses in laboratory settings.

Exopolysaccharides (EPS) are high-molecular-weight sugar polymers secreted by bacteria, fungi, and algae. Numerous studies have investigated their anti-inflammatory and antioxidant properties. EPS treatment has been associated with reduced production of pro-inflammatory mediators such as tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), cyclooxygenase-2 (COX-2), and nitric oxide. At the same time, antioxidant enzymes, including superoxide dismutase (SOD), have been reported to recover following EPS treatment.

Research has also shown that EPS can suppress activation of the nuclear factor kappa B (NF-κB) signalling pathway by reducing its phosphorylation and nuclear translocation. Experimental liver toxicity models have further demonstrated improved hepatocyte viability at therapeutically relevant EPS concentrations. Collectively, these findings suggest that EPS may regulate underlying inflammatory pathways rather than simply reducing the outward signs of inflammation.

As of 2024 trial data, several microbial metabolites are now in active clinical trials. LPS-derived bacteriocins are being evaluated for immune modulation indications. SCFAs themselves are being tested in inflammatory and metabolic disease contexts. Urolithin A, a metabolite produced when gut bacteria break down ellagitannins from pomegranates and other fruits, is being evaluated for age-related cellular decline and mitochondrial health. The presence of these compounds in active trials is what separates the field from speculative microbiome research. Therapeutic application is no longer a future possibility. It is currently happening, with regulatory approvals being earned compound by compound.

The biology described here is not remote research at Parul University. The Inflammation Research Lab led by Dr. Anupam Jyoti at the Parul Institute of Applied Sciences works on resveratrol in sepsis and metabolite-based approaches to chronic obstructive pulmonary disease, both funded through the Department of Science and Technology (DST) and the Indian Council of Medical Research (ICMR) channels, with a 2026 publication confirming the lab is actively producing output. The MNRDC’s instrumentation infrastructure supports the experimental work that turns this research into reportable data, including the scanning electron microscopy that produces the NET formation imagery used in published research. The April 2026’s MNRDC workshop  brought the working biology covered in this article into direct student training, with seventeen students walking through the experimental design behind each major finding.