According to BBC report of a cross-sectional observational study “The make-up of the bacteria found in human faeces may influence levels of dangerous fat in our bodies.” The study showed that people who had fewer different types of bacteria in their faeces were more likely to be obese.”
The Western diet has a definite role in promoting an obesogenic gut microbiota.
Gut microbiota is being increasingly recognized as an important factor connecting genes, environment, and immune system. The human gut hosts an enormous number and variety of microorganisms, including at least 1014 bacteria belonging to ∼1,000 species. The genome size of this microbial organ, collectively named microbiome, exceeds the size of the human nuclear genome by two orders of magnitude and provides important biological and metabolic functions that cannot be performed by researchers. Genomic and environmental factors at the basis of mutual host-microbiota interactions have been intensely investigated with metagenomic and metabolomic approaches in the last 5 years.
Understanding Role of Gut bacteria in rising obesity
- In a study conducted by Gordon & colleagues, they noticed that germ-free mice (i.e., raised in the absence of microorganisms) had 40% less total body fatthan conventionally raised mice, even if their caloric intake was 29% higher than that of conventionally raised animals.
- In a further key experiment, Backhed et al. fed germ-free or conventionalized mice a high-fat, high-carbohydrate Western diet. After 8 weeks, germ-free mice gained significantly less weight and fat mass than conventionalized mice and were protected against the Western diet-induced glucose intolerance and IR. In contrast to the previous experiment, germ-free and conventionalized mice had similar energy content in their feces, suggesting a more efficient energy harvest from the diet might not be the only factor responsible for the fat mass gain of the conventionalized mice.
Further experiments have demonstrated that gut microbiota may modulate both sides of the energy balance equation, namely energy harvest from the diet, energy storage as triglyceride, and energy expenditure through fatty acid oxidation, and that may mediate diet-induced obesity, IR, and diabetes.
Bacteroides and Firmicutes are the two most dominant groups of bacteria present in the gut. Obese people are more likely to have a smaller proportion of Bacteroides than Firmicutes within the gut microbiota while this ratio of Bacteroides to Firmicutes increases as fat mass decreases, which was confirmed by two groups of people who were placed on two different types of low-calorie diets . Obese people had higher levels of Firmicutes bacteria present in their gut microbiota but they also had more genes present in the gut that were able to breakdown indigestible foods which suggests that these bacteria can absorb more calories from their food. Therefore, a change in the bacterial composition within the gut microbiota will affect weight. This was the first clear correlation between how the gut microbiota determines body weight.
Nutritional intervention with nutrients with prebiotics properties can help manage the problem. Probiotic Foods Sources are:
- Dark Chocolate
- Kefir- creamy dairy drink similar to yogurt.
- Sauerkraut- made from fermented cabbage
- Miso Soup
- Microalgae- such as spirulina, chorella, and blue-green algae.
- Tempeh: a fermented, probiotic-rich grain made from soy beans.
- Kimchi: an extremely spicy and sour fermented cabbage.
- Kombucha Tea
A patient lost 4stone 7lbs in nine weeks after being placed on a diet of ‘whole grains, traditional Chinese medicinal foods and probiotics’, and this was because it had reduced the bacterium’s presence in the patient’s gut to ‘undetectable’ levels.