These bacteria and fungi make up the gut microbiome. Their complex interaction is associated with the human body and different body functions such as immunity, digestion, protection and secretion of various beneficial substances including vitamin B12, riboflavin, vitamin K and thiamine.
A person gets first introduced to microorganisms while passing through the mother’s birth canal and slowly develops diversified microflora with time. The diversity and load of a person’s gut microorganisms can affect metabolic health like one’s resistance to invading pathogenic organisms. Unbalanced gut flora can result in chronic gastric diseases such as Crohn’s disease, irritable bowel syndrome, celiac disorders, and food poisoning, as well as can even induce autoimmune diseases such as rheumatoid arthritis, diabetes, multiple sclerosis and muscular dystrophy.
Dysbiosis is the imbalanced state of the gut microbiome, which results in a decrease in beneficial bacteria like firmicutes and bacteroides and an increase in harmful bacteria like Clostridia, Klebsiella and Enterococcus and other species affecting the gut health seriously, leading to stomach cramping, frequent diarrhoea, constipation, indigestion and stomach bloating.
Some bacteria can break down plant molecules such as starch, increasing digestion. Probiotics are beneficial live bacteria that when ingested, promote the colonisation of helpful microflora and possibly cure stomach upset, loose motion and food poisoning. Prebiotics are foods such as plant fibres that help in the proliferation of probiotics. This interaction of pro-pre and gut microbiome improves overall metabolic health.
Certain microorganisms such as Akkermansia muciniphila feed on the intestinal mucus layer, inducing the excess synthesis of mucus. This helps form a thick layer of mucus barrier that hinders infection by external pathogens and the entry of toxic metabolites, providing extra protection. This also prevents unwanted inflammatory responses. This bacterium also affects the metabolism of glucose and fats. A balanced gut microflora ensures proper signalling of satiety (hunger) hormones, thereby controlling obesity.
Some bacteria can break down choline and L-carnitine residues derived from red meats, eggs and high-fat animal proteins. This results in the production of trimethyl-N-oxide that directly contributes to atherosclerosis, artery hardening, plaque formation and subsequent heart attack. Studies show that people who consume probiotics or have a healthy gut flora have higher HDL levels or good cholesterol and thus have a healthy heart.
Gut microorganisms can also affect blood sugar levels by acting on the liver to break down glycogen storage, increase one’s energy balance and decrease obesity. Studies show that a decline in gut microflora may be associated with an onset of diabetes (Type 1) by inducing inflammation and insulin resistance.
Research in mice shows that some strains of E.coli can secrete proteins that can result in protein misfolding, resulting in the loss of their functions. These abnormal proteins can reach the brain through the vagus nerve in the gut and cause various brain diseases such as Alzheimer’s disease, Parkinson’s disease, etc. Gut bacteria such as Akkermansia muciniphila, secretes niacinamide (VitB3) that improves these neural damages.
Moreover, gut microflora prompts the secretion of serotonin from the intestinal area. Serotonin is an important neurotransmitter that affects important brain functions, and 90% of serotonin is secreted from the GI tract. Serotonin plays an important role in controlling sleep, moods, digestion, blood coagulation, healing wounded tissues, appetite and bone health.
Breast milk in mothers is rich in Lactobacillus and Bifidobacterium, which increase the immunity of infants.
Gut bacteria can stimulate various inflammatory responses and help foster adaptive immunity in humans. Adaptive immunity is an essential defence mechanism that elicits a quicker immune response to known invading pathogens and toxins.
Well-balanced gut microbiota is an important aspect of our health, and has a profound impact on our digestive properties and brain functions such as lowering blood pressure and cholesterol levels. This can be obtained by following a nutritional diet plan, refraining from sedentary lifestyles, consuming pro and prebiotics and working out regularly.