The Relationship Between Gut Microbiota and Obesity

It is known that one of the fundamental elements of healthy living is regular and balanced nutrition, along with weight control. While excess weight ranks among the leading risk factors for many diseases, obesity itself remains a significant global health issue. Nutrition and Diet Specialist Harika Özkaya Yurttadur explained that the disruption of gut flora, also known as the microbiota, plays a critical role in the development of obesity and related diseases. Yurttadur pointed out that restoring a healthy balance to the microbiota plays an essential role in the weight loss process and in the fight against obesity. 

Does Gut Flora Affect Weight Control?

Nutrition and Diet Specialist Yurttadur stated that there is a complex relationship between gut microbiota and obesity. According to research, changes in the structure of the microbiota can be both a cause and a consequence of obesity. She explained: "Although the mechanisms of the relationship between gut microbiota and obesity are not fully understood, it is believed that probiotics, prebiotics, and exercise positively affect gut microbiota and obesity management.” 

There Are 10 Times More Microorganisms Than Cells in Our Body

Yurttadur, a Nutrition and Diet Specialist at Yeditepe University Kozyatağı Hospital, shared the following information: "There are approximately ten times more microorganisms in the gastrointestinal system than cells in the entire body, and they possess 150 times more genetic diversity than the human genome.

In our body, there are over 2,000 bacterial families and more than 15,000-35,000 species, most of which reside in the intestines. These communities of microorganisms in the human body are referred to as microbiota. Individuals go through various life stages that affect their gut microbiota, including infancy, adolescence, adulthood, pregnancy, breastfeeding, and old age. During these life stages, microbiota continues to change depending on the individual's lifestyle and diseases."

What Is Dysbiosis?

According to Yurttadur, the disruption of the balance in gut flora (microbiota) is called dysbiosis. Dysbiosis primarily affects the gut-brain axis through the modulation of food intake, energy regulation, and fat storage, via immune, neural, or metabolic pathways, leading to obesity and obesity-related metabolic disorders.

Which Foods Disrupt Microbiota Balance? 

High-Fat and Low-Fiber Foods Negatively Impact Microbiota

Obesity is a widespread chronic metabolic disorder linked to long-term health problems on a global scale. Yurttadur highlighted that, among the many factors contributing to obesity, the most common is the energy imbalance between intake and expenditure. "Studies have shown a strong link between certain microbiota profiles and obesity," she said. Yurttadur added, "Especially diets high in fat and low in fiber can negatively affect gut microbiota, leading to microbial imbalances that cause obesity. It has been observed that obese individuals have a different composition of gut microbiota compared to lean individuals. When lean and obese individuals are compared, it is found that obese people have altered gut microbiota characterized by reduced microbial diversity (in microbiome analyses of obese and overweight individuals, Bacteroides fragilis and Lactobacillus species are reported to be higher in comparison to lean individuals and are associated with an increased BMI; Bifidobacterium species, on the other hand, are found to be higher in lean individuals and negatively correlated with BMI). It has been especially noted that individuals prone to obesity have a higher abundance of bacteria that increase energy production and storage. These bacteria may cause food to be digested more efficiently and stored as fat in the body."

How to Maintain Microbiota Balance?

Probiotics and Prebiotics Play a Positive Role in Maintaining Balance

Yurttadur explained that with the identification of the interactions between gut microbiota and obesity, it has been shown that probiotics and prebiotics can positively alter the composition of microbiota, controlling both appetite and obesity. She added: "Probiotics are live microorganisms that, when consumed in sufficient quantities, regulate microbial balance in the host's gut and have positive health effects. Most probiotics belong to the Lactobacillus and Bifidobacterium families. Prebiotics are food substances that reach the large intestine without being digested in the upper gastrointestinal tract, where they stimulate the growth or activity of certain bacteria or bacterial groups in the flora, positively affecting the host's health."

Foods That Are Sources of Probiotics and Prebiotics

Nutrition and Diet Specialist Harika Yurttadur listed the foods that are sources of probiotics and prebiotics: "Probiotic-rich foods that you can add to your diet include probiotic yogurt, kefir, cheese, pickles, turnip juice, vinegar, boza (a traditional fermented drink), and tarhana (a fermented Turkish soup base), all of which are both easily accessible and easy to consume. Prebiotic-rich foods that you can add to your diet include chicory, artichokes, leeks, onions, tomatoes, asparagus, bananas, garlic, wheat, barley, rye, and honey."