Blame it on our naivety, ignorance or hypochondria, we tend to associate the word ‘bacteria’ with illness and poor health.
Combined in equal parts with our ancestral disdain (because our microbiota is mainly a replica of that harboured by our parents) for salads and greens (the richest source of fibre on which these bacteria thrive), our gut bacteria have now been pushed to the brink of near extinction.
So where does this diminishing biodiversity leave you? For starters, let’s just say, more incapacitated than you thought!
Role of gut bacteria
The bacterial consortium residing in our gut is an important determinant of our optimal wellness. From assimilation of essential nutrients in food, synthesising of Vitamin K, digestion of cellulose in green vegetables, to promotion of angiogenesis and regulation of enteric nerve function, these bacteria perform myriad jobs in our body.
Furthermore, these commensal bacteria strengthen our immunity by enhancing barrier integrity, thus preventing pathogens and harmful bacteria from invading our systems.
Other benefits rendered by gut microflora include absorption of minerals, transformation of bile acid and destruction of toxins, genotoxins and mutagens. Some bacteria even prevent formation of kidney stones.
To put the acuity of their roles in perspective, consider the ‘hygiene hypothesis’ which posits that disruption of microbiome in the body leads to onset of autoimmune diseases due to compromised immunity of the individual.
Other studies have found association between depleted microbiome and diseases such as Type II Diabetes, and conditions like allergies and food sensitivities.
Gut microbiome and lack thereof has been implicated in obesity because these organisms contribute in appetite regulation and energy harvest from food.
An unhealthy or imbalanced bacterial flora has also been alleged in conditions such as intestinal inflammation, cardio-metabolic diseases, and colorectal, prostate and gastric cancers which occur due to production of genotoxins by bacteria and microbial metabolism of carcinogens’ in food.
This upheaval is triggered by a number of factors such as environmental exposures, genetic makeup, age, use of antibiotics and most importantly, diet.
Dietary fibre is given way less credit than it is due. It does so much more than just regulating bowel movements. For instance, research links high fibre diet with lesser incidence of breast cancer in females as increased consumption of fruits and vegetables during adolescence cuts back cancer risk by 24%.
Scientific data accrued over several decades shows plausible ties between fibre rich diet, thriving of gut microbiota and low cancer incidence. Additionally, variety in type of fibre consumed benefits the human body even more as it tends to diversify the bacterial population because different bacteria specialise in metabolism of different type of fibre.
A rich gut microbiome translates into increased cellular nutrition and less chances of acute and chronic inflammation.
Direct impact of low fibre diet on gut microbiome was recently studied by a team of microbiologists at Stanford University. Experiments conducted by microbiologist Justin Sonnenburg and his team using a mice model found that low fibre diet did indeed render the gut microbes virtually extinct.
Using mice loaded with identical gut flora, the investigators fed them high fibre diet and then randomly switched half of them to low fibre chow for a period of seven weeks. As expected, the microbiota of low fibre group badly suffered, with colonial count of as many as 60 different microbes waning dramatically.
Not only this, but the effect cascaded through generations as the researchers found that the off springs of test subjects had narrower microbiomes, and even more bacterial species blinked out if these mice consumed low fibre diet like their ancestors.
The change was also found to be irreversible in fourth generation of mice even when fed high fibre diet subsequently. Other studies show that the gut microbiome of industrialised populations is much less diverse than those residing in rural areas and consuming a high fibre diet of vegetables and fruits.
So the next time around, don’t pass the salad for chicken nuggets. You will be doing yourself an enormous favour as it will take more than a tub of yogurt to reverse the impact of your oil and salt rich diet on your friendly gut residents.