SCFA is a crucial bridge for the intestinal microbiota to exert its significant impact

What are SCFAs?

Short-chain fatty acids (SCFAs), also known as volatile fatty acids (VFAs), are typically organic fatty acids with 1-6 carbon atoms. The main SCFAs include acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, and hexanoic acid.

How are SCFAs produced?

SCFAs are the metabolic products of the gut microbiota. About 90% of SCFAs in the human body are produced by anaerobic microorganisms fermenting indigestible carbohydrates, while the remaining part is produced by dietary intake and protein metabolism. Normal human intestines produce about 50-100 mmol SCFAs per day. Acetic acid, propionic acid, and butyric acid account for about 95% of the total SCFAs in the colon, with a ratio of approximately 3:1:1.

What are the influencing factors of SCFAs production?

The main production site of SCFAs is the colon, and its species and quantity mainly depend on the composition of gut microbiota, digestion time (the time it takes for food to pass through the intestines), host-microbial metabolic flux, and the fiber content in the host's diet. The main bacteria that affect the production of short-chain fatty acids include Bacteroides, Bifidobacterium, Eubacterium, Ruminococcus, Streptococcus, Clostridium, and Staphylococcus.

SCFAs and gut health

The SCFAs produced by the gut microbiota play an important role in maintaining gut health. They exert their functions in multiple ways, including energy regulation, maintaining the integrity of the gut barrier, participating in immune regulation, inducing tumor cell differentiation and apoptosis, and directly regulating host health.

SCFAs and Diseases

1. Neurological Diseases

SCFAs can regulate the maturation and function of microglial cells, affecting neurological diseases through the brain-gut axis, such as Parkinson's disease and Alzheimer's disease. SCFAs can also alleviate anxiety.

2.Immune Diseases

Butyric acid can regulate the production, trafficking, and function of innate and adaptive immune cells.

3.Cancer

Butyric acid can inhibit the proliferation of certain tumor cells and induce tumor cell differentiation and apoptosis, making it applicable in the treatment of colon cancer.

4.Cardiovascular and cerebrovascular diseases

Propionic acid can reduce vascular inflammation and atherosclerosis.

5.Gastrointestinal Diseases

SCFAs can reduce diarrhea associated with intestinal electrolytes. Butyric acid is used to treat congenital chloride diarrhea. SCFAs in moderate concentrations can inhibit the growth of pathogenic bacteria such as Escherichia coli and Shigella, protecting the intestines. High concentrations of SCFAs can damage the intestinal mucosa, possibly participating in the development of necrotizing enterocolitis in newborns;

6.Metabolic Diseases

SCFAs can promote insulin secretion and reduce fat accumulation, making them a potential treatment for obesity and type 2 diabetes.

MetwareBio provides targeted short-chain fatty acids metabolomics service which can conduct absolute quantitative detection of 11 short-chain fatty acids at one time. 

References

1. Dalile B, Van Oudenhove L, Vervliet B, Verbeke K. The role of short-chain fatty acids in microbiota-gut-brain communication. Nat Rev Gastroenterol Hepatol. 2019 Aug;16(8):461-478. doi: 10.1038/s41575-019-0157-3. PMID: 31123355.

2. ZhangF, Wan Y, Zuo T.et al. Prolonged Impairment of Short-Chain Fatty Acidand L-Isoleucine Biosynthesis in Gut Microbiome in Patients WithCOVID-19. Gastroenterology. 2022 Feb;162(2):548-561.e4. doi:10.1053/j.gastro.2021.10.013. Epub 2021 Oct 21. PMID: 34687739;PMCID: PMC8529231.

3. Wang R, Yao L, Meng T.et al. Rhodomyrtus tomentosa (Ait.) Hassk fruitphenolic-rich extract mitigates intestinal barrier dysfunction andinflammation in mice. Food Chem. 2022 Nov 1;393:133438. doi:10.1016/j.foodchem.2022.133438. Epub 2022 Jun 8. PMID: 35696951.

4. Wu JT, Sun CL, Lai TT.et al. Oral short-chain fatty acidsadministration regulates innate anxiety in adult microbiome-depletedmice. Neuropharmacology. 2022 Aug 15;214:109140. doi:10.1016/j.neuropharm.2022.109140. Epub 2022 May 22. PMID: 35613660.

5. Lavelle A, Sokol H. Gut microbiota-derived metabolites as key actorsin inflammatory bowel disease. Nat Rev Gastroenterol Hepatol. 2020Apr;17(4):223-237. doi: 10.1038/s41575-019-0258-z. Epub 2020 Feb 19.PMID: 32076145.