Gut Bacteria May Influence Food Cravings

09/30/2019 | 5 min. read

Dr. David Williams

Dr. David Williams

I’ve been studying and researching bowel bacteria and their effects on health for decades. For most of that time, I felt like the lone voice in the wilderness. Talking about the importance of regular bowel movements was strange enough, but talking about beneficial bugs in the colon was even stranger. But things are changing.

Every month, new discoveries are being made about the significance of establishing and maintaining the proper bowel flora. We’ve seen how an imbalance can be an underlying cause of everything from cancer and heart disease to mood and anxiousness.

Addressing this area of your health is becoming more crucial with each passing day. Never before has a society taken more drugs, used more herbicides, pesticides, and food preservatives, consumed more artificial, non-fermented foods, and embraced more habits that disrupt and destroy the beneficial bacteria in the body.

Microbes Are In Control

As individuals, we tend to believe that we are in control of our bodies. After all, we can decide the amount of exercise we get, how we think, and what we eat and drink. The truth of the matter, however, is that most of us don’t have as much control as we imagine.

I’ve said many times that we live in a sea of microorganisms. Our bodies are covered inside and out with these microorganisms. The number of bacteria living just within the human body outnumbers human cells 10 to 1. And it now appears these bacteria may actually manipulate our decisions about what we eat and drink.

Researchers have now shown that microbes in the gut manipulate both our behavior and our mood by changing the nerve signals of the vagus nerve. (The vagus or 10th cranial nerve directly connects the digestive tract to the base of the brain.)

Sneaky Little Bugs

The idea that microbes in the digestive tract could control what we eat may sound a little farfetched, until you take a closer look.

We have a very diverse community of microbes in the gut. They all have one primary goal: survival (theirs, not necessarily ours). Different species prefer different nutrients. Some like sugar, while others prefer fat. Rather than just passively live off whatever comes their way, they can chemically alter the nerve signals that the brain uses to monitor activity in the gut. By releasing certain chemicals, they can change taste receptors, inducing cravings and making us prefer one food over another.

When you experience rumbling in your belly, it’s not just the sign of an empty stomach. The brain has detected that blood sugar levels are running low and it has sent out a signal to trigger stomach contractions. Researchers at Louisiana State University were recently able to prove this by chemically blocking this function of specific brain cells. As long as these brain cells were blocked, hunger sensations and stomach grumblings ceased.

The discomfort and stomach grumbling you experience with low blood sugar levels is called “hypoglycemia awareness.” Through their direct connection to the brain via the 10th cranial nerve, gut microbes use their influence in a similar manner to make us feel uncomfortable and experience specific types of food cravings.

Researchers are beginning to see how these bacteria can release toxins to make us feel bad when we consume something not to their liking, and then chemically “reward” us by producing chemicals that make us feel good when we make the “right” choices.

As long it’s the beneficial bacteria, then there’s no problem. Researchers have demonstrated how the use of specific bacteria improve mood while other strains of bacteria increase anxious behavior. We see this with strains of beneficial bacteria like Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-175.

When the wrong bacteria have control of the gut, the battle between the species for food can take a different turn. Their dietary interests are not always aligned with our dietary goals, and it often shows in the way we feel and act. We can experience mood disorders and anxiousness. We might lose our ability to control blood sugar fluctuations, which can eventually lead to diabetes. By influencing our cravings and moods to suit their own needs, gut bacteria are an underlying cause of obesity and heart disease, two of the most common conditions that plague our society. And the list of associated problems will certainly grow as more research becomes available.

Bacteria live in their own micro-environments within our digestive tract. They have direct communication with our immune, nervous, and endocrine systems. Over time, they quickly figure out exactly which chemical signals they send will provide them with the most amount of food they need to survive and flourish. The bacteria in our digestive tract don’t just sit idly by and hope to survive. They manipulate us.

We Can Manipulate Back

Fortunately, we can also manipulate our gut microbes through the use of prebiotics, probiotics, fermented foods, and fecal transplants.

The warm, moist, fertile environment of the gut provides the ideal growing medium for bacteria. Under these conditions, bacteria multiply very rapidly. We’ve all experienced just how quickly a mild case of food poisoning or “stomach flu” can develop. Research has shown there are significant changes in bacterial counts within 24 hours of a change in diet. In fact, bacteria reproduce at such a high rate that taking huge amounts of a probiotic isn’t generally necessary to dramatically change the microbiome. It’s more important that you take the right strains and a product that will ensure they reach the intestinal intact.

It’s also imperative that you replenish these bacteria regularly. The beneficial bugs are under constant attack from our water, food supply, and other factors.

While mainstream medicine is starting to accept the importance of probiotics, the main thrust of the pharmaceutical industry seems to be looking at this research from a different viewpoint. You don’t see much emphasis being placed on the need for probiotics and fermented foods in the diet. There’s not much money to be made there. They are starting to focus on using targeted antibiotics that kill undesirable bacteria strains while leaving the beneficial ones intact. It has to be frustrating for them to realize that inexpensive and readily available treatments can quickly prevent and/or resolve a long list of health problems more effectively than any drug ever will.

Dr. David Williams

Meet Dr. David Williams

For more than 25 years, Dr. David Williams has traveled the world researching alternative therapies for our most common health problems—therapies that are inexpensive and easy to use, and therapies that treat the root cause of a problem rather than just its symptoms.

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