The Relationship Between Diet Culture And The Microbiome

For a long time, carbohydrates have been antagonized by diet culture as the source of weight gain and the symbol of an unhealthy living lifestyle. However, we cannot generalize all carbohydrates as having a detrimental effect on our gut microbiome. Fibers, for instance, feed microbes in the gut, such as Bacteroides and Actinobacteria, while starches increase Firmicutes counts while decreasing Blautia counts [4]. A diverse intake of carbohydrate in our diets allows for a healthy balance of different microbes in our microbes; this concept is similar to the importance of diversity in the wild, where a species with variety is more likely to survive a sudden event. While eating less carbohydrates may seem like an intuitive choice for our health, in reality, our gut microbes rely on carbohydrate intake as fuel to carry out daily functions.

Sugars are another form of carbohydrates. One study has found that sugars increase the abundance of Proteobacteria while decreasing Bacteroidetes, therefore creating an imbalance within the gut that is correlated with inflammation and metabolic dysregulation [5]. We can divide sugars up into simple carbohydrates, which are absorbed easily by enzymes in the body within the first few minutes after ingestion, and oligosaccharides, which are not as easily digested and depend on glycoside hydrolases (which are produced by the microbiome of the gut) in the digestion process [4].

How does knowing these details inform our understanding of diet culture? Carbohydrates are difficult to deem as “bad” as popular diet culture suggests–each type, in moderation, feeds some form of microbes in the microbiome. While low-carb diets can be beneficial to those who are consuming an excess amount of processed sugars and refined carbs, we must remember that grains, vegetables, fruits, and even starches in moderation, are important for maintaining a balance in our gut. Some diets such as ketogenic diet encourage cutting out all carbohydrates, if possible–while short-term weight loss may occur as a result of cutting out carbohydrates, the diet is not sustainable long-term due to its impacts on our body, specifically on the gut microbiome, on blood pressure, nutrient deficiencies, and even on the heart [6].

Another common diet trend emphasizes eating within a certain window of time each day, and fasting throughout the other period. Intermittent fasting is said to prevent overeating and give the body a regular cycle, as well as be helpful in targeting obesity and metabolic syndrome. Beyond this, fasting also is an aspect of different religions and cultures–for example, in the Islamic religion, Ramadan fasting is an example of intermittent fasting called time-restricted eating [7].

How do intermittent fasting and the gut microbiome interact with each other? In previous studies, it has been found that intermittent fasting has a positive influence on anti-inflammatory processes, which are often associated with the gut. It is found that, based on a review of multiple studies, there is a general trend of increases in microbiome diversity from intermittent fasting practices. However, there were some discrepancies—for example, Bacteroidetes increased in a group of Pakistanis who did intermittent fasting, but decreased in the Chinese group. Intermittent fasting reveals something else about our gut microbiomes–our cultural practices play
a role in how our bodies have been adapted. Overall, based on cultural diets and eating patterns, different cultural groups react differently when introduced to a pattern of eating like intermittent fasting.

In conclusion, some factors promoted by mainstream diet culture do have beneficial effects on the body, while others have a more complex story in their effects. Whenever following a certain trend, it is important to consider the effects that it may have on the body, beyond immediate effects such as potential weight loss. Sustainable diets ensure that our gut microbiomes are at optimal functioning. Perhaps instead of using diet culture as a way of antagonizing certain food groups, we should use this trend to shed light on the small microorganisms in our bodies that keep us healthy.