Nutrition, nutrition, nutrition! Nutrition is big news these days because, well, nutrition is everything. Nutrition is nature’s medicine. Nutrition is life. Diets, cleanses, and detoxes are also mainstream in the health and wellness world for people trying to reset their body, lose weight, and live a healthier lifestyle. These types of short term diet changes have their place and benefits. I believe doing a gut reset, liver detox, or whole body cleanse from time to time can be very beneficial for overall health. Short term diets should not be relied upon, however, for whole body health. Your long term diet is the most important determining factor for overall health. This may seem obvious, but it goes far deeper than just healthy eating for weight loss and heart health. Long term diet can make or break the health of your entire body.
This holistic approach to health and nutrition is important, because the nutritional content of the food you intake affects the bacteria living in your gut. The gut microbiota is basically like another organ. It is a complex interconnected ecosystem of microorganisms that are essential to the health and wellness of the host (that’s you). How so? The gut microbiome affects brain development, mood, depression and anxiety, the immune system, inflammation, digestive function, and gut permeability (7). These tiny warriors provide benefits to us by the production of short chain fatty acids (SCFA), vitamin K, fermentation of undigested food particles, protection and barrier function, and immunologic regulation (5). The gut microbiota functions on a delicate balance of beneficial and harmful bacteria. Many things determine the diversity of the gut bacteria and the species of organisms it contains, including development, age, genotype, environment, sex, antibiotic use, stress, and you guessed it…your diet. (3)
Please remember, these statements have not been reviewed by the FDA and are not intended to cure, diagnose, treat, or prevent any medical condition. This is not intended as medical advice and should in no way replace a conversation with a healthcare provider. This is my own personal research; if something interests or inspires your, please do your own research of the topic and speak with your healthcare provider about it.
Establishment at birth
In order to understand the microbiota, we have to start from the beginning. A tiny fetus is living in a completely sterile environment. In a natural birth, a baby is born without any medication and is held against mom’s body thus exposing him or her to mom’s vaginal and skin flora. This is the beginning of baby’s gut bacteria. From here on out, pretty much everything begins to shape baby’s gut flora. Studies have shown babies born via c-section vs. vaginally have different dominant strains of bacteria, as well as babies fed formula vs. breastmilk (3). Over 700 microbial species have been identified in human breast milk (5), and this exposure continues shaping the infant microbiota in breastfed babies. Gestational age, antibiotic use, pets, and other family members also begin to affect baby’s gut flora (7).
Development of the gut flora
The biggest change toward a permanent and stable adult gut flora begins when the baby starts solid food (3). This time of life is crucial, as the gut bacteria reaches it’s permanent adult state by age three and becomes far more resilient (7). In the absence of antibiotics, diet is the main controlling factor of the gut microbiome, as was shown in a study comparing African children to Italian children. In this study, the dominant gut bacterial species were largely determined by the main food source of the population, whether it be plants, meat, or carbohydrates (5). The gut microbiota adapts to the nutritional content of the diet. In fact, it can even code for special enzymes specific to common foods of a culture— the Japanese have a species of bacteria that codes for an enzyme used to digest seaweed (3).
Resiliency in adults
The gut microbiota is resilient in adulthood. It is more similar within one person on a day to day basis than between different people. Monozygotic twins may even have a 50% difference in gut bacteria (3). Again, long term diet is the biggest determining factor of gut bacteria aside from situations like antibiotic use, which can wipe out the good bacteria and allow overgrowth of harmful organisms.
How diet affects the gut microbiome
As many of us know, the high fat, high sugar, processed food diet of America is not ideal. This kind of diet is linked not only with inflammation and obesity but leaky gut, depression, and many other health problems (7). Leaky gut, or increased intestinal permeability may lead to high levels of endotoxins in the blood stream that contribute to chronic inflammation and autoimmune disease (7).
An interesting study on gnotobiotic (sterile) obese mice showed the obese mice were able to lose weight when transplanted with the gut bacteria of thin mice (3). When fed a diet high in saturated fats, this effect was diminished (3). In other studies, mice fed a high fat, high sugar diet for 28 days were compared with mice fed a diet of chow. Surprisingly, changes in the gut microbiome were documented as early as 3 days; this change included a decreased in Lactobacillus, a highly studied and beneficial group of gut bacteria (2). Interestingly enough, at around 14-28 days the microbial changes began to stop, although some species were more sensitive to changes than others (2). After about a month of a similar diet, the gut bacteria stayed fairly consistent. This shows overall, long term diet is crucial in the determination of the permanent microbiome.
Aside from immune system problems like inflammation and autoimmunity, poor gut health can affect cognitive function along the gut-brain axis. As stated earlier, consumption of a high fat, high sugar diet may impair gut permeability, which contributes to chronic, systemic inflammation and cognitive impairment (8). Poor diet has also been associated with damage to the blood brain barrier in as little as 90 days (8). Cognitive impairment includes but is not limited to ADHD, anxiety, depression, autism spectrum disorders, and behavioral disturbances. Studies have linked autism spectrum disorders with major gut bacterial disturbances and a slight increase in intestinal Candida (12).
Antibiotics and gut disturbances
I am not against proper antibiotic use. They have their place and they save lives. However, they should not be taken lightly or misused, and I believe when using them one should absolutely be on good probiotic.
Apart from diet, antibiotic use is the other major factor in determining the gut microbial balance. The gut microbiome can become severely affected by antibiotics (9,10). After antibiotic use is stopped, the gut microbiota has lost much of its diversity. The recovery time varies in the individual, but without any treatment the disturbances can persist long term (10). Different microbial species are affected by antibiotics at a varying rate, but many times pathogenic organism overgrow in the absence of a healthy gut flora, this including Clostridium difficile and Candida albicans. Clostridium difficile is an anaerobic microorganism that causes severe and persistent diarrhea in patients who have taken antibiotics, many times who are hospitalized. It is incredibly contagious and increasingly more difficult to treat.
Candida albicans is a commonly known yeast that is normal in small amounts in a healthy intestine but a menace when it becomes overgrown (11). Once Candida begins taking over the gut, it may lead to many health problems including chronic vaginal and skin yeast infections, digestive disturbances, immune system malfunction, and neural problems (13). A diet high in sugar and grains encourages Candida growth, increases symptoms, and contributes to leaky gut (13.) For many, the only way to heal their gut, reduce overgrowth, and decrease intestinal permeability is to eliminate sugar and grain from the diet entirely. Although it goes greatly against the standard American diet, this practice is becoming more and more common for many people struggling with cognitive disorders, autoimmune disease, digestive disorders, skin problems, chronic inflammation, allergies, anxiety, and depression.
How do probiotics fit into all of this? A probiotic is a beneficial microorganism that provides benefits to the host. Probiotic supplements and probiotic rich foods are becoming more and more mainstream, and for good reason. Not only can they improve immune function, they have also been shown to impact digestive function. They work by improving the microbial equilibrium in the intestine and activating fermentation of soluble fiber to produce short chain fatty acids (SCFA) (5). SCFA are the main nutrient source of the intestinal cells in the colon, and they also play a role in increasing blood flow and water absorption (1). Probiotics have also been shown to positively impact intestinal permeability (7). S. boulardii can decrease diarrhea in children, and other probiotics have been used to treat diarrhea caused by antibiotic use (6). Case studies have shown that probiotics may increase the number of beneficial gut flora (5).
Studies have shown that probiotics may not always colonize the host, which is why it is important to make them a regular part of your diet (6). In one study, a diet that restricted fermented foods led to a decrease in the innate immune response, a decrease in fecal leukocytes (white blood cells that fight infection), and a decrease in Lactobacillus in the stool (6). Therefore, to keep stable levels of probiotics in the gut, one must intake supplements or fermented foods frequently (5). It is important to note that the effects of probiotics will be different for different people based on variations in gut flora, age, and other environmental factors (5). Also, not all probiotic supplements or fermented foods are created equally; this difference in quality will certainly impact results.
A healthy gut sets you up for a healthy body
Why is it so important what the dominating bacterial species is in your gut? Each organism provides a separate benefit to the host. For example, the lactic acid forming bacteria such as Lactobacillus and Bacteroides are the main produces of SCFA. The microbiota is so complex that little is known about the vast amount of functions and benefits it provides. Although we don’t know exactly what every single organism does, we do know that keeping the gut diverse and balanced is essential to good health. A healthy and diverse gut microbiome is necessary for proper function of the immune system, brain, gut, and body as a whole. Because long term diet is such an important determining factor, it is absolutely essential to adopt long term healthy eating habits which include a diet low in sugar, processed food, refined grains, and unhealthy fats, and high in whole, unprocessed, organic, and nutritious foods. It also means that when you have established a long term highly nutritious diet, a cheat meal or dessert every once in awhile isn’t going to set you back as long as you are not battling a disease.
Simple summary of this post
For those of you would prefer not to read about studies and research, here are the main takeaways of this post.
1. Gut bacteria and gut health are related to the proper function of the immune system, digestive system, brain, and body as a whole. A balanced and diverse gut microbiome leads to a healthy gut.
2. Long term diet is a major determining factor in how balanced and diverse your gut bacteria is; the microbiome adapts to the diet of its host. A cleanse or detox is beneficial, but more importantly is how you eat long term.
3. To keep the system balanced, a good approach is to eat a diet low in sugar, processed food, refined grains, and unhealthy fats, and high in whole, unprocessed, organic, and nutritious food as well as daily fermented foods or high quality probiotic supplements (especially when taking antibiotics).
- Short-Chain Fatty Acids (SCFA)
- A High-Fat High-Sucrose Diet Rapidly Alters Muscle Integrity, Inflammation and Gut Microbiota in Male Rats
- Dietary effects on human gut microbiome diversity
- Diet and the development of the human intestinal microbiome
- Health-beneficial effects of probiotics: Its mode of action
- Probiotics: 100 years (1907-2007) after Elie Metchnikoff’s Observation
- Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders
- Gut to Brain Dysbiosis: Mechanisms Linking Western Diet Consumption, the Microbiome, and Cognitive Impairment
- Short- and long-term effects of oral vancomycin on the human intestinal microbiota
- Antibiotics, microbiota, and immune defense
- New evidences on the altered gut microbiota in autism spectrum disorders.
- Intestinal Candidiasis The Yeast Syndrome
Please consult a doctor or healthcare provider before making any health changes, especially if you have a specific diagnosis or condition. The information on this site should not be relied upon to determine diet, make a medical diagnosis, or determine treatment for a medical condition. The information on this website is not intended to be a consult with a healthcare provider or provide medical advice. Any statements or claims about the possible health benefits from food or supplements have not been evaluated by the Food & Drug Administration (FDA) and are not intended to diagnose, treat, prevent or cure any disease. Full disclaimer here.