Food Cravings May Originate In Your Belly, Not Your Brain

Skinny people, especially svelte doctors and trim dietitians, and even some professionals who have not worked out their own weight issues, are always telling fat people that their problem is a lack of willpower. Calories in have to equal calories out, they say over and over again, so if you weigh too much, they problem is that you are eating too much. And if you are eating too much, the problem is your lack of willpower. Your fat is your fault.

Or maybe it isn't.

Bacteria Power May Be Greater than Brain Power

There is an increasing body of scientific evidence that bacteria in the gut override signals in the brain to cause you to eat the foods that give them an edge over competing microbes. Microorganisms, primarily in the large intestine, may send signals to the vagus nerve, the long nerve down the middle of your body that regulates both heartbeat and appetite, to cause you to eat the foods that are good for them rather than the foods that are good for you.

Dr. Carlo Maley, a PhD director of the Center for Evolution and Cancer at the  University of California at San Francisco, stated in a press release that "Bacteria are manipulative. There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals and others not."

A paper Dr. Maley wrote with Dr. Joe Alcock, an MD, and other scientists, published in the journal Biofactors, explains that different kinds of bacteria have different nutritional needs. Provatella bacteria, for instance, thrive on carbohydrates. They generate chemicals that send a message to the nervous system for their hosts to eat more sugar. 

They send out signals that encourage their hosts to eat fiber-rich fruits, vegetables, and grains. Many other kinds of bacteria are generalists, and can survive on many kinds of nutrients, but have their preferences for maximum growth. Many different kinds of bacteria can hijack the nervous system and override the signals from the brain that encourage dietary restraint so that dieters indulge in foods not so much because they want them as because the bacteria in their digestive tracts insist on them.

One Hundred Million Chances to Stimulate Your Appetite

The vagus nerve connects to over 100 million neurons that line the digestive tract. The activities of these millions of neurons or orchestrated by the vagus nerve, and the vagus nerve in turn sends signals from those neurons to the brain. This important nerve can be "toned down" so that appetite decreases, or become hyperactive so that appetite greatly increases.

See Also: Probiotics For Weight Loss?

They can release serotonin to increase stomach activity and bowel movement when they want to "clear out" the digestive tract for their preferred nutrients. They can even change the digestive tract's taste sensors so that certain foods taste better or worse.

How You Can Take Back Control Over Your Appetite

In addition to stimulating appetite and accelerating digestion so you want to eat more, bacteria can punish you for not eating the foods they want by releasing toxins. Diarrhea can sometimes be a bacterial temper tantrum to punish you for not eating what your bacteria want, not just an invasion of your digestive tract by diarrhea-causing microbes. So what can you do to take back control over your appetite when the bacteria in your system sabotage your best efforts to control what you eat so you can lose weight?

The best answer seems to be to work with the bacteria that help you keep your appetite in check. Bifidobacter bacteria feed on fiber. Fiber is good for you in a number of ways.  It slows down the speed of food through your digestive tract. You feel fuller longer. You don't want to eat as much.

And the bacteria that feed on fiber in your large intestine use it to make food for themselves with a byproduct called butyric acid, which reduces inflammation in the colon and also reduces the risk of colon cancer.

How can you get the Bifidobacterium bacteria you need into your digestive tract. This really isn't hard at all.

• Eat cultured dairy products (yogurt) or cultured soy milk or coconut milk that contains live cultures of Bifidobacterium. It's important that the label includes the description "live cultures," since pasteurized milk without live bacteria added back will not do anything for your bacterial balance.
• You can also take probiotics that contain the needed Bifidobacterium, either in capsule or "shot" form. The Canadian natural products maker Alive! makes a drink mix containing these and many other helpful strains of bacteria.
• In addition to consuming the probiotics that provide the bacteria your body needs, eat at least small amounts of the prebiotics that feed friendly bacteria. Prebiotic foods include just about anything with soluble fiber (wheat bran contains insoluble fiber), but especially foods like chicory, radicchio, prunes (which also contain chemicals that increase bowel movement), and fresh fruit. Sauerkraut, pickles, fermented soy products such as miso, and kimchi provide other bacteria that help fight off the "bad" bacteria that make you want to eat more.

It doesn't take long for friendly bacteria to help you get your appetite back under control. They begin releasing neurotransmitters that encourage your brain to direct you to fiber-rich foods about 24 hours after they get into your system. 

See Also: Why Belly Fat is Unhealthy and Why Soluble Fiber may be Your Lifesaver

What can go wrong if you use probiotics as a diet aid? The answer is, not a lot. However, if your doctor puts you on any kind of antibiotics while you are dieting, be sure to replace the healthy bacteria your body needs every day to make sure the diet-friendly bacteria you need maintain their numbers.