Gut Bugs and Constant Cravings

From the moment we're born, our bodies are getting colonized by thousands of microbiota. These microorganisms have a profound effect on our health, including our metabolisms.

Lean and obese individuals have different amounts of gut flora and diversity. Lean people typically have more diversity among their gut microorganisms. Gut microbes like firmicutes (which are overrepresented in obese folks) are more efficient at extracting energy from food and storing dietary fat, meaning that these individuals will store more fat from eating the same food as a leaner individual.

Junk food can cause an increase in nasty, obesogenic gut flora, which cause us to crave more foods that feed these obesogenic bacteria. This creates an endless cycle of craving low nutrient density, calorically dense foods that make it more difficult to lose fat.

The Power of Prebiotics

One way to improve gut health is to include prebiotics in your diet. Prebiotics are foods high in special kinds of bacteria that promote the growth of "good bacteria." Some of these fibers include beta-glucan, inulin, psyllium, pectin, fructo-oligosaccharides, as well as other oligosaccharides commonly included as fiber on food labels.

Prebiotic-rich foods include: leeks, garlic, onion, jicama, asparagus, bananas, barley, oats, wheat bran, dried fruits (figs, dates, prunes), chickpeas, and red kidney beans.

The Benefits

Prebiotics impacts our guts in several ways:

  • Improves gut flora. Greater diversity in gut flora positively impacts our digestive systems and the way we break down and store foods.
  • Stimulates appetite-regulating hormones. Our hormones can influence how often we're hungry and how much we eat.
  • Increases satiety after meals. Feeling full longer keeps total caloric intake in check.
  • Impacts absorption of macro and micronutrients. Prebiotics improve the absorption of certain minerals that we're commonly deficient in, like magnesium and calcium, as well as improves our insulin sensitivity.

Appetite Science

Gut flora has a direct impact on appetite suppressing and stimulating hormones. Within our hypothalamus we have a gut hormone receptor that impacts circulating levels of appetite-regulating hormones, namely pro-opiomelanocortin (POMC), which is appetite-inhibiting, and neuropeptide Y (NPY) and agouti-related peptide (AgRP), two appetite-stimulating neurons. Signals from our gut affect the circulation of these neurons, culminating in changes in our energy expenditure and eating behaviors.

A 7-week study using rats on a high saturated fat diet supplemented with a prebiotic (glucomannan) showed an increase in adipose adiponectin levels and a reduction in hyperglycemia. Adiponectin regulates energy homeostasis, improves glucose metabolism, and fatty acid oxidation. Higher levels of circulating adiponectin is associated with a leaner body.

References

  1. Mullin, G., MD. (2015, July 05). Solving the Obesity Epidemic One Gut Bug at a Time. Retrieved February 09, 2016, from www.medicaldaily.com
  2. Perry, B., & Wang, Y. (2012). Appetite regulation and weight control: The role of gut hormones. Nutr Diab Nutrition and Diabetes, 2(1).
  3. Vázquez-Velasco, M., González-Torres, L., Benedí, J., Bastida, S., Sánchez-Muniz, F., Keijer, J., & Schothorst, E. V. (2014). Glucomannan Plus Spirulina-Enriched Squid Surimi Prevents Ampk Inhibition On Zucker FA/FA Rats Fed Hyperlipemic Diets. Clinical Therapeutics, 36(8).

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