Gut Flora and the Human Body

The human gut has its own gut flora (gut microbiota) – a complex community of microorganisms that live in the digestive tracts of humans. Gut flora is beneficial for health in many ways. Some gut microbes benefit the host by fermenting dietary fibre into short-chain fatty acids, which are then absorbed easily by the gut. They also play a role in synthesising vitamin B and vitamin K. Gut flora also acts as an immune organ by metabolising any foreign particle present in the gut. The composition of human gut flora changes over time and with changes in the diet. It has also been found that people who suffer from certain diseases (such as inflammatory bowel disease, irritable bowel disease and allergy) have a micro flora that is different to that of healthy people, although it cannot be concluded that the altered micro flora is a cause or a consequence of the disease. The impairment of the gut flora has been correlated with many inflammatory and autoimmune conditions. Here are some scientifically established facts: Supplemental and diarrhoea probiotics When antibiotics are consumed, they result in an imbalance in the gut flora by killing them. This may lead to an alteration in the digestion and absorption process, in turn leading to osmotic diarrhoea. Supplemental probiotics have shown to produce a protective effect in this situation. Probiotics are suggested as a possible treatment for various forms of gastroenteritis and in cases of acute diarrhoea. Consumption of curd and avoidance of milk is thus recommended during diarrhoea. Ingestion of certain active strains may help lactose-intolerant individuals tolerate more lactose than they would otherwise. Probiotics are ineffective in preventing allergies in children. A few studies suggest that consumption of supplemental probiotics may help to control high blood pressure. Studies suggest that the consumption of probiotics reduces serum cholesterol levels, probably by breaking down bile-embedded cholesterol in the gut, thus inhibiting its reabsorption. Probiotics may influence pathogens, causing infections by means of competitive inhibition – that is, by competing for growth. Some studies suggest that probiotics may decrease the incidence of respiratory-tract infection, rotavirus infections and dental caries in children and travellers’ diarrhoea in adults.

Side Effects of Supplemental Probiotics

Although consumption of supplemental probiotics is considered to be safe, there are concerns about their safety in some cases. The manipulation of the gut microbiota is complex. Scientists doubt that ingestion of microbes may cause bacteria–host interactions. It has been found that individuals with short-bowel syndrome, central venous catheters and cardiac-valve disease as well as premature infants may be at higher risk for adverse events. Passage of viable bacteria from the gastrointestinal tract to the internal organs can occur in individuals with inflammatory bowel disease. It has also been suggested that probiotics cause obesity in humans, although it hasn’t been proved scientifically. Many scientific communities discourage the use of probiotic dietary supplements and recommend improved health through gut-flora modulation by maintaining long-term dietary changes such as consumption of adequate calorie and a fibre-rich diet.