In my new book and upcoming public television show, The Skinny Gut Diet, I talk at length about how gut microbes are in control of your health, and how your particular gut balance determines whether or not you will gain weight. Although it seems farfetched at first, everything seems to finally make sense once you realize that you are not entirely responsible for those extra 20 pounds.
Think about it: Who hasn’t been on an assortment of diets, only to gain back every pound—and then some? Or who hasn’t hit that dieting plateau when no matter what you do, the scale doesn’t budge? As it turns out, your gut bacteria may be to blame. That’s right—the fact that you are overweight may be the result of having the wrong bacteria in your gut.
In a fascinating review recently published in the journal BioEssays, researchers discuss evidence for the role bacteria play in triggering our food cravings. The bacteria in your gut need certain foods—particularly sugars and carbohydrates—that benefit them. So they trigger your cravings, causing you to overeat so that they can get the food they need.
“Bacteria within the gut are manipulative,” said Carlo Marley, PhD, one of the authors. “There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not.”
Gut microbes work in four main ways to manipulate behavior and mood, leading to overeating and weight gain. Gut microbes:
- Alter communication with the nervous system via the vagus nerve (which connects the gut to the brain).
- Change taste receptors.
- Produce toxins to make us feel unwell.
- Release chemicals that make us feel good.
There is evidence that gut microbes have an effect on mood, a topic Dr. Smith and I have blogged about before. The researchers also discuss the ability of certain gut microbes to induce feelings of being unwell, which can trigger a person to overeat. One example they give of this phenomena is colic. Babies with colic have altered gut bacteria and are commonly overfed, which can lead to weight gain. Could it be that the gut microbes in these babies are simply trying to get fed? Scientists say yes. And other bacteria may be doing something similar in your gut.
“Gut microbes may manipulate eating behavior by hijacking their host’s nervous system,” stated the researchers.
Not only that, but many gut microbes produce neurotransmitters and hormones, such as serotonin (the feel-good hormone) and dopamine (the reward neurotransmitter). Many gut bacteria also produce compounds that are almost identical to leptin, ghrelin, peptide YY, and neuropeptide Y, all hormones that regulate satiety and hunger. The secretion of these compounds in the gut may affect how much you crave and how much you eat.
The researchers go on to discuss the effects of gut bacteria on weight gain, a topic I delve into in The Skinny Gut Diet, and we have also discussed here on the blog. They go on to discuss the use of probiotics for weight loss, as I do in the book and on this blog.
Interestingly, they discuss the possibility that a lower diversity of gut microbes is associated with more unhealthy eating behaviors. It’s a vicious cycle. When excess food is eaten, microbes have extra food to consume, which result in an increase in certain bacteria that favor those foods and a decrease in other bacteria. The dominant species then exert a stronger effect on the host (that’s you!) that leads to overeating, which further feeds the dominant species. This cycle lowers the overall diversity of gut microbes and leads to food cravings and weight gain. Yikes!
“Until we have a better understanding of the contributions and interactions between individual microbial taxa, it may be more effective to focus interventions on increasing microbial diversity in the gut,” note the researchers.
The good news is that you aren’t stuck with your bacteria. Gut bacteria respond quickly to changes in diet. To break the cycle, you will need to begin with your plate. Foods high in starches and sugars are the biggest culprits. Nonstarchy vegetables, low-sugar fruits, fermented foods, healthy fats, and protein will help you regain your gut balance, and your waistline. For more on how to do just that, preorder my book.
I regularly blog about the brain benefits of fish oil because the science behind them is so extensive and I want to pass the knowledge on to others. When you have the knowledge to heal your body, you become your own health advocate, and you realize how much power you have to change your health.
In yet another study highlighting the brain power of fish oil, published in the journal Alzheimer’s and Dementia, researchers found that people who regularly take fish oil supplements were least likely to suffer from mild cognitive impairment or Alzheimer’s disease when compared to those people who did not take fish oil. The only exception was in people with the genetic variant known as APOE4, which is known to increase risk of Alzheimer’s.
The researchers analyzed data from 819 people with cognitive function ranging from normal to Alzheimer’s. Those people who regularly took fish oil supplements (and who did not have the APOE4 gene) had better cognitive function and less brain shrinkage in two areas of the brain critical to memory and thinking when compared to people who did not take fish oil.
“These findings may suggest a potential role for fish oil supplements by reducing neurodegeneration [brain damage] over time,” noted the researchers.
When looking for a fish oil supplement, you want to look for the following features:
High potency: You want to know how much omega-3 is in each capsule, not how much fish oil. Look for a softgel that contains at least 1,000 mg omega-3 per softgel.
Purity: Look for the IFOS (International Fish Oil Standards) seal to be sure that your fish oil exceeds published international standards for the lowest levels of toxins.
Freshness: Look for fish oil in dark-colored glass bottles and softgels to protect the oils from light and moisture. In addition, look for added lipase, which helps with digestion of the oils.
Enteric coating: Look for enteric coated fish oil softgels that deliver omega-3s directly to the intestines where they are absorbed.
The 100 trillion bacteria that live inside the human digestive tract are the subject of many studies currently underway. Researchers the world over are trying to figure out which microbes constitute a “healthy microbiome,” which microbes protect our health, and which cause disease. Many advances have already been made, but there is still much we don’t know about the creatures that inhabit us.
In a recent study published in the journal Genome Biology, researchers collected daily bowel movements and tracked the lifestyle habits of two people over the course of a year. They tracked habits such as diet, sleep, mood, leisure activity, and exercise. They found that the bacterial populations are relatively stable over time, but fluctuate on a daily basis in response to certain lifestyle factors.
“On any given day, the amount of one species could change manifold, but after a year, that species would still be at the same median level,” noted Eric Alm, PhD, lead researcher. “To a large extent, the main factor we found that explained a lot of the variance was the diet.”
It’s nice to know that we have some control over our bacterial balance by the foods we eat. Eating more dietary fiber increased certain beneficial populations of bacteria, such as Bifidobacteria. High-fiber foods were found to change the gut bacterial composition rapidly. Interestingly factors such as mood and sleep did not have as much of an effect on bacteria populations.
During the course of the study, each of the two subjects experienced an event that changed their bacterial balance significantly. One subject experienced food poisoning that completely altered gut balance so much so that it did not fully recover. The other subject visited a third-world country and experienced diarrhea for two weeks, resulting in a change in bacteria balance that eventually returned to normal after return to the United States.
This study gives us a small glimpse into the dynamic world of our inner inhabitants. It shows that we can positively affect our gut balance by eating the right foods, but it also shows us the vulnerability of our gut bacteria to disease. Eating healthy not only for our own sake, but for the sake of our bacteria, is becoming more important than ever.
Long-term heavy use of alcohol can lead to brain damage and increased risks of dementia, so the search is on for treatments that offset this damage. In a recent study published in the Public Library of Sciences ONE journal, researchers tested the effects of fish oil on brain cells exposed to high levels of alcohol. The fish oil was found to protect against inflammation and neuron cell death.
Using an animal model, researchers exposed rat brain cells to concentrations of alcohol equivalent to about four times the legal limit for driving, a concentration seen in alcoholics. The alcohol-exposed cells were compared to those exposed to the same high levels of alcohol, in addition to the fish oil compound DHA (docosahexaenoic acid). They found a 90 percent reduction in inflammation and death of neurons (brain cells) in those cells exposed to alcohol plus DHA when compared to those exposed to alcohol alone.
Further studies are needed to confirm these results in humans, but the researchers are hopeful.
“Fish oil has the potential of helping preserve brain integrity in chronic alcohol abusers,” noted Michael Collins, PhD. “At the very least, it is unlikely that it would hurt them.”
Important to note, this study is not a green light to drink all you want and just take some fish oil. The best way to protect brain health is to not drink too much. But for those (hopefully infrequent) times when you do, be sure that you are taking fish oil on a regular basis. You may be able to offset some of the damage.
One of the best ways to get diabetes under control is by eating a low-carbohydrate diet. Carbohydrates include mostly sugars and starches, with fiber making up a smaller portion. Starches—as found in breads, pastas, pastries, crackers, etc.—break down into sugar in the digestive tract, so you can think of starches as “hidden sugars.” A diet high in carbohydrates is really a diet high in sugar, which triggers insulin resistance and high blood sugar, leading to diabetes. Yet for some reason, reducing carbohydrate intake has not been widely recommended. The starches have been overlooked while sugar gets all the blame.
In a recent review published in the journal Nutrition, researchers offer 12 points of evidence in support of a low-carbohydrate diet as first-line treatment of type 2 diabetes, and in conjunction with insulin in people with type 1 diabetes.
“Diabetes is a disease of carbohydrate intolerance,” stated Barbara Gower, PhD, one of the researchers. “Reducing carbohydrates is the obvious treatment. It was the standard approach before insulin was discovered and is, in fact, practiced with good results in many institutions. The resistance of government and private health agencies is very hard to understand.”
Here are some highlights from the review:
- High blood sugar is the most prominent feature of diabetes. Dietary carbohydrate restriction has the greatest effect on decreasing blood sugar levels.
- During the epidemics of obesity and type 2 diabetes, caloric increases have been due almost entirely to increased carbohydrate.
- Although weight loss is not required for benefit, no dietary intervention is better than carbohydrate restriction for weight loss.
- Replacement of carbohydrate with protein is generally beneficial.
- A diet high in total and saturated fat does not correlate with risk of cardiovascular disease.
- Fats in the blood are more affected by eating a diet high in carbohydrates than a diet high in fats.
- The best predictor of vascular complications (heart disease) in people with type 2 diabetes is blood sugar control. That is, better blood sugar control, less complications and vice versa.
- Dietary carbohydrate restriction is the most effective method of reducing high triglycerides and increasing HDL (“good”) cholesterol.
- Patients with type 2 diabetes on carbohydrate-restricted diets reduce and frequently eliminate medication. People with type 1 usually require lower insulin.
- Intensive lowering of blood sugar levels by restricting dietary carbohydrates has no side effects comparable to the effect so intensive diabetes medications.
The low-fat diet craze, which was supposed to lead to better health, has only worsened the situation of chronic disease in this country. People are beginning to get the message that we need fats in the diet, but they are slow to realize that we also need to cut the carbs.
If the points above aren’t enough to convince you to try to reduce your carbohydrate intake, I’m not sure what is. My last book, Heart of Perfect Health, delves into the topic of high blood sugar as it relates to heart disease (because it very much relates to heart disease), and recommends a low-carbohydrate, high-fiber diet complete with plenty of fiber.
“The low-fat paradigm, which held things back, is virtually dead as a major biological idea,” stated lead author, Richard David Feinman, PhD. “Diabetes is too serious a disease for us to try to save face by holding onto ideas that fail.”
What most low-carb diets miss, however, is the fiber component. Because fiber is technically a type of carbohydrate, low-carb diets can also be low in fiber. But I view fiber as a freebie carb. As long as it’s not found in starchy foods, fiber is your friend. The best source of fiber comes from non-starchy vegetables and low-sugar fruits. Not only do you get plenty of digestive benefits, but you also get plenty of nutrients when you eat these foods.
Inflammation is one of the main ways in which the body heals itself. When inflammation is employed in the short term, it comes and goes when needed, and is resolved in due time. When you get a cut or bruise, or when your body fights a cold, you usually feel worse for a short while before you feel better—that’s inflammation at its best. Acute inflammation is an important part of the body’s function. It becomes a problem when the inflammation is chronic. Chronic inflammation contributes to most, if not all, chronic disease, and it can be triggered by a wide range of factors.
In a recent study published in the Proceedings of the Royal B Society journal, researchers found that low birth weight and insufficient or no breastfeeding increases the risk of inflammation later in life.1 To measure inflammation, blood levels of C-reactive protein (CRP), a well-known marker of systemic inflammation, were measured in over 15,000 adults aged 24 to 32 years old. Those infants who weighed more than 6.18 pounds at birth and those who were breastfed for at least three months were less likely to have inflammation in young adulthood.
“Breastfeeding provides nutritional and immunological support to infants following delivery and has sensitive period effects on immune development and metabolic processes related to obesity—two potential avenues of influence on adult CRP production,” noted the researchers.
Although they measured CRP at one point in time, they excluded data for anyone who also exhibited symptoms of infection so that they would have a better marker of chronic vs acute inflammation.
Current breastfeeding guidelines in the United States recommend exclusive breastfeeding to six months of age, followed by continued breastfeeding to at least one year. Yet only a small percentage of infants meet these recommendations. Brenda and I have blogged many times on the benefits of breastfeeding. Most importantly, breastfeeding helps to boost the beneficial gut bacteria in infants, which helps set them up for a lifetime of better health. Breast milk contains the prebiotic GOS (galactoligosaccharide), which feeds good bacteria in the gut. It also contains beneficial Bifidobacteria, as some researchers recently discovered.
It would have been interesting to see the gut bacteria levels in the participants of this study. My guess is that those with longer breastfeeding (and lower inflammation) would have a healthier balance of gut bacteria.
If you have been on the fence about breastfeeding, please know that it’s one of the best things you can do for your infant. Strive to breastfeed for a minimum (longer, if possible) of one year. If you are unable to breastfeed for health reasons or because you do not produce enough milk, a probiotic supplement formulated for infants is recommended.
McDade TW, Metzger MW, Chyu L, et al., “Long-term effects of birth weight and breastfeeding duration on inflammation in early adulthood.”Proc Biol Sci. 2014 Apr 23;281(1784):20133116.
The connection between gut bacteria and weight gain is a subject of great interest among researchers. It’s a topic of great interest to me, too! The search is on for probiotic therapies that prevent weight gain. In a recent study published in the Journal of Clinical Investigation, Vanderbilt University researchers discovered a protective effect against weight gain of a genetically modified probiotic bacteria, E. coli Nissle 1917.
Although most people think of food poisoning when they think of E. coli, only one specific E. coli strain causes disease (E. coli O157:H7). Most E. coli strains are actually harmless or even beneficial.
The researchers genetically modified the E. coli strain to produce a compound called NAPE (N-acylphosphatidylethanolamine), which is normally created in the small intestine in response to eating. NAPE is converted to NAE (N-acylethanolamine), which is known to reduce food intake and weight gain.
Mice eating a high-fat diet ingested NAPE-producing bacteria for eight weeks and were found to have lower food intake, body fat, insulin resistance, and fatty liver when compared to mice receiving bacteria not genetically modified to produce NAPE. The protective effects lasted at least four weeks after probiotics were no longer ingested. Twelve weeks later the mice still had lower body weight and body fat compared to control mice.
“Of course, it’s hard to speculate from mouse to human,” noted lead researcher Sean Davies, PhD, “But essentially, we’ve prevented most of the negative consequences of obesity in mice, even though they’re eating a high-fat diet.”
While this study is interesting, I must say that I have reservations about genetically modifying bacteria. We simply don’t know the long-term consequences. If this NAPE compound is something that we naturally produce in the intestines, it seems to me that we can find another way to optimize its production in the gut. Perhaps this research can help us to better understand how to affect weight gain, but without resorting to genetic modification. In all, this study still supports the connection between gut bacteria and weight gain. It shows that one simple chemical produced by gut bacteria has the ability to have many positive effects on weight loss-related health.
You may have heard that omega-3 fats are good for your joints—and you’re right, particularly when it comes to inflammation. Most studies investigating omega-3 for joint health have looked at rheumatoid arthritis, an autoimmune disease that causes inflammation in the joints. Omega-3 supplementation has been shown to reduce the need for non-steroidal anti-inflammatory drugs (NSAIDs) and reduce symptoms and inflammation in these patients.
A new study published in the Annals of the Rheumatic Diseases investigates the role of omega-3 fats on the other main type of arthritis—osteoarthritis. Osteoarthritis affects about 27 million people in the United States and involves loss of cartilage in joints, which causes pain, stiffness, and loss of mobility.
In the study, the researchers used an animal model and administered three different diets: one high in saturated fat, one high in omega-6 fats, and one high in omega-6 fats with additional omega-3. Those diets high in saturated and omega-6 fats caused a worsening of arthritis while the diet with added omega-3 helped slow joint deterioration.
“While omega-3 fatty acids aren’t reversing the injury, they appear to slow the progression of arthritis in this group of mice,” stated Farshid Guilak, PhD. “In fact, omega-3 fatty acids eliminated the detrimental effects of obesity in obese mice.”
Next, the researchers plan to study the effects of omega-3 fats in people with osteoarthritis induced by injury. I look forward to the results.
Because osteoarthritis triggers inflammation, many integrative physicians recommend omega-3 fats for their benefits on inflammation. Omega-3s help to balance the inflammatory effects of a diet high in omega-6 (the reason the omega-6-rich diet in the study above made the arthritis worse). Many people have insufficient levels of omega-3 due to the high prevalence of omega-6 fats in the diet.
Eating fish high in omega-3 (salmon, sardines, and herring, for example) and taking a fish oil supplement while lowering omega-6 intake (replace your vegetable oils with olive or coconut oil) will help to balance your omega-3/6 ratio and promote healthy joints.
You have likely heard of bisphenol A (BPA), the hormone disrupting chemical found in many plastics. In fact, you may even purchase ‘BPA-free’ plastics in an effort to minimize your exposure to BPA. Many of us do. But you might want to rethink your approach based on some new research. The chemical that manufacturers use to replace BPA is BPS, or bisphenol S. As the name suggests, BPS is similar to BPA. Due to this similarity, some researchers have questioned the safety of BPS.
In a recent study presented at the meeting of the International Society of Endocrinology and the Endocrine Society, researchers found that young zebrafish (which exhibit similar development as humans, surprisingly) had increased hyperactivity and brain changes when they had been exposed to BPS during brain development stages early in life.
“BPS, termed the safe alternative to BPA, may be equally as harmful to developing brains,” noted Deborah Kurrasch, PhD, lead researcher. “Society must place increased pressure on decision makers to remove all bisphenol compounds from manufacturing processes.”
BPA has been linked to many conditions, including obesity, reproductive cancers, and hyperactivity in children. Could it be that BPS induces similar harmful effects?
This is not the first study to suggest BPS is not the safe alternative we think it is. And it won’t be the last. Until they find a better, safer substitute, your best bet is to avoid plastic containers as much as possible. Opt for glass instead, which is about as safe as it gets when it comes to chemicals. Glass is inert, so it won’t leach any toxins. Be sure to share this news with others, because I suspect many people don’t realize that ‘BPA free’ may not be as safe as we are led to believe.
One out of every three adults has high blood pressure (hypertension), yet only about half of them have their blood pressure under control. Another one out of three adults has prehypertension, which means that they are on their well on their way to joining the first group. With two-thirds of American adults suffering from hypertension or prehypertension, the search is on for effective ways to lower blood pressure.
A recent systematic review and meta-analysis published in the American Medical Association journal Hypertension found that probiotics are an effective means of lowering blood pressure. The researchers analyzed nine studies that included 543 participants and found that probiotic consumption lowered systolic blood pressure by 3.56 and diastolic blood pressure by 2.38 mm Hg when compared to those adults who did not take probiotics.
The blood pressure lowering effects were even stronger in people taking higher doses of probiotics and when they were taken for a period of at least eight weeks. They also found greater effect from consuming multiple rather than single strains of probiotics. These findings suggest that taking a high-dose, multi-strain probiotic for a longer duration is more effective at lowering blood pressure.
“We believe probiotics might help lower blood pressure by having other positive effects on health, including improving total cholesterol and low-density lipoprotein, or LDL, cholesterol; reducing blood glucose and insulin resistance; and by helping to regulate the hormone system that regulates blood pressure and fluid balance,” stated Jing Sun, PhD, lead researcher.
The reduction of blood pressure in this analysis, although modest, is similar to that found in another analysis of salt reduction of 2,000 mg daily. Even modest blood pressure reductions are beneficial, however, and have been associated with a 22 percent reduced risk of cardiovascular death, heart attack, or stroke.
The benefits of probiotics for conditions outside the gut are growing at a rapid pace. This new analysis is excellent evidence that what happens in your gut affects the rest of your body. Keep taking your probiotics.