Factors that adversely affect the normal gut flora
So far I have shown the importance and the health-enhancing role of the normal gut flora. That there is a normal gut flora is a paradox but it is true that there are some bacteria in the gastrointestinal tract that are referred to as friendly bacteria. These friendly bacteria actually recognize, attack and destroy the pathogenic, unfriendly bacteria.
There are certain factors that adversely affect these friendly bacteria and when this is allowed to happen, the functions of the normal flora will be lost to one degree to the other. Knowledge of these factors will help us deal with and eliminate them.
The effect of diet on the normal gut flora has been noticed as early as a baby is born. Apart from the influence the mother’s vagina (the birth canal) or skin has on the baby’s gut flora, the early diet adopted for the child plays a significant role on the composition of the normal gut flora. The early feeding of a baby is either by breast milk or infant formula. The trend in these modern days is shifting towards infant formula. As this happens, the effect is clearly noticed in the composition of the gut flora. Studies have confirmed that breast milk-fed children are able to digest and absorb nutrients from their diet more completely than formula-fed ones. Furthermore, the immune enhancing and antimicrobial activities are more with breast milk-fed babies.
As an individual grows older and even unto adulthood, diet continues to be the most important factor in determining the composition of the normal gut flora. Studies have shown a clear difference in the gut flora if the diet is mainly of fresh fruits, vegetables and fibre as against a diet of animal proteins, fats and refined carbohydrates (sugars). The gut flora associated with the fruits, vegetables and fibre were found to be richer and more abundant in such organisms that metabolize insoluble carbohydrates. These are the type of organisms that metabolize lactose in children with lactase deficiency.
The conclusion arrived at in many of the studies carried out was that a diet of fruits, vegetables and fibre affected the normal gut flora more positively than any other diet.
Effect of antibiotics on gut flora
Broad-spectrum antibiotics can destroy the microorganisms that make up the normal gut flora. The result of this destruction is that there is a reduction of these organisms and this will, in turn, result in a negative effect on the health of the host. The ability of the gut flora to metabolise and absorb digested nutrients completely will be lost. Also, the use of antibiotics can cause increased growth of pathogenic organisms, which can cause infection in the large intestine. These antibiotics can also cause the development and growth of drug-resistant strains of microorganisms.
Interestingly, researchers also found a relationship between the normal gut flora and the geographical location of an individual. Even though it was discovered that location played a role in the composition of the gut flora, this was also associated with the difference in diet in the different parts of the world. For instance, among the African population whose diet was based more on vegetables and fruits, the composition of the gut flora was different from that of the Caucasians who ate more of animal based diet.
Probiotics, prebiotics and symbiotics
Probiotics are live microorganisms that are believed to provide health benefits when consumed.
Prebiotics are non-digestible fibre that passes through the upper gastrointestinal tract unchanged until it gets to the large intestine. In the large intestine it acts as a substrate for the normal flora providing nourishment and growth of the good microorganisms there.
This topic is so important that I will leave it until next week Thursday.