Much of the initial understanding about how the gut and its associated bacteria contribute to obesity and metabolism emerged from the lab of biologist Jeffrey Gordon, MD, at the Washington University School of Medicine in St. Louis.
Gordon’s team discovered that when eight-week-old germ-free mice are inoculated with the fecal contents of ordinary mice, their fat content increased by 57 percent, even though they ate 29 percent less animal chow.
1) Gut Bacteria Affect Fat Hormones (fasting induced adipose factor)
Gordon’s group found that adding intestinal microbes into germ-free mice was associated with increased transport of carbohydrates from the intestine to the liver. This interfered with signals from a gut hormone that inhibits a particular enzyme, in this case an enzyme that normally delivers fat from the liver to the fat cells. The end result is more fat accumulation in the liver and abdomen.
Tip: Like it or not, we all have bacteria in our gut. The key is to eat a diet rich in color, fiber and protein to foster the growth of the good guys. Supplementing with whey protein, inulin, and Bifidobacteria and Saccharomyces boulardii based-probiotics may help.
2) Imbalanced Gut Bacteria Create Gut Inflammation, Insulin Resistance
The presence of harmful intestinal bacteria correlate with the degree of weight loss or gain later in life, independent of calories.
Researchers have found that babies delivered vaginally are immediately inoculated with their mother’s vaginal flora, which is dominated by healthy lactobacillus and Prevotella strains. And scientists know that infant inoculation with maternal bacteria is among the most powerful environmental variables molding our gut, and hence our metabolism.
In contrast, babies born by C-section are inoculated by the more pathogenic bacteria, common to the skin and hospital air, such as Staphylococcus aureus and Clostridium difficile. Incidentally, studies link child and adult microflora profiles rich in these bacteria to both obesity and diabetes.
A recent study of 1,255 children found that the prevalence of obesity in children born via Cesarean section by age three is twice that of children born vaginally.
Tip: Eat organic foods, rich in color and phytonutrients. Limit consumption of animal products given antibiotics and drink filtered water. Advise “parents-to-be” to birth their children naturally, breast feed and avoid antibiotics during the first year of life.
3) Low Bacterial Diversity Slows Down Your Metabolism
A recent analysis of several human studies suggests that obese people tend to have a lower level of bacterial diversity, a higher level of Staphylococcus aureus, more intestinal bacterial overgrowth, and a lower level of Bifidobacteria compared to lean people. Bifidobacteria are well known to be more “friendly” strains, while Staphylococcus aureus are known to be more immune stimulating.
Tip: A diverse diet, rich in phyto-nutrients will increase bacterial diversity. Eat as many herbs, spices and color as you can.
4) Methane Producing Bacteria Slow Down Your Gut and Increase Food Absorption
Researchers at Cedar-Sinai Medical Center in los Angeles found that obese people have greater levels of intestinal methane-producing bacteria known as Methanobrevibacter smithii. This bacteria slows down intestinal transit time by up to 60 percent, prolonging the period during which intestinal bacterial are exposed to food. As a result, more calories are absorbed from that food, and there is more weight gain. That’s one reason why even if you were to eat fewer calories than you actually burn, imbalances in your gut microflora might cause you to gain weight.
Tip: The oral probiotic bacteria, Streptococcus salivarius DSM 14685 has been shown to reduce sulfur-producing bacteria, at least in the mouth. It’s worth considering.
5) High-Fat, High-Carbohydrate Diets Can Make You Fat: the role of endotoxin
I feel that everyone should know how eating the western diet of high-calorie diets in general shift our gut ecology, increasing the absorption of endotoxin, which cranks up inflammation in the gut, liver, and fat tissues; resulting in fat gain.
The ensuing inflammation and deranged metabolism has been coined, metabolic endotoxemia.
Harvard scientists recently found that supplementing the diets of mice with an enzyme called alkaline phosphatase, the absorption of endotoxin is reduced, preventing fat gain and metabolic disorders. Thankfully we all have high levels of this enzyme found on the surface of our intestinal wall.
Tip: Bile acids help to reduce endotoxin absorption, which is why it’s so important to be mindful and chew when you eat (bile release is part of the parasympathetic response). Avoid acid-suppressing medications, artificial sweeteners, and acidic foods, such as hard cheeses and refined carbohydrates, as they reduce alkaline phosphatase’s protective ability.
If you eat a high-fat diet, make sure to pair it with some color and fiber. (This will minimize endotoxin absorption.)
Chapter 8 of Belly Fat Effect unveils the whole story about gut bacteria, the circadian clock system and metabolism, fat burning, appetite, and more.