HOW CAN GUT MICROBIOME AFFECT YOUR WEIGHT

The gut microbiome plays a surprisingly influential role in determining weight by affecting how our bodies process and store nutrients, regulate appetite, and manage fat storage. Here’s a breakdown of how this works:

1. Nutrient Absorption and Metabolism

• Certain gut bacteria can increase the amount of calories extracted from food, which means that even with the same diet, people with different microbiomes may absorb different amounts of energy. Some gut microbes break down complex carbs and fibres that would otherwise pass through undigested, leading to increased calorie absorption.
• Gut microbes also produce short-chain fatty acids (SCFAs) like butyrate, propionate, and acetate, which provide energy to the host and may influence fat storage and energy expenditure.

2. Influence on Appetite and Satiety

• Gut bacteria communicate with the brain through the vagus nerve and the release of certain metabolites that affect hunger hormones, such as ghrelin and leptin. Some bacteria can promote the release of GLP-1 and PYY, hormones that promote satiety, potentially helping to reduce appetite.
• Conversely, an imbalance in the gut microbiome, or dysbiosis, may lead to higher cravings, especially for sugar and processed foods, by altering these hormone levels.

3. Impact on Inflammation and Insulin Sensitivity

• A balanced microbiome supports low inflammation, while an imbalanced microbiome can lead to chronic, low-grade inflammation, which is linked to insulin resistance. Insulin resistance can make it easier for the body to store fat, especially around the abdomen, and harder to burn it off.
• Some bacteria, like certain Firmicutes strains, have been associated with a higher risk of obesity due to increased inflammation and calorie absorption, while others, like certain Bacteroidetes, are associated with leanness.

4. Effect on Fat Storage and Energy Balance

• The microbiome affects the body's fat-storage pathways by influencing gene expression related to fat accumulation. Certain bacterial strains increase the activity of lipoprotein lipase (LPL), which facilitates the storage of fatty acids in fat cells, contributing to weight gain.

5. Role of Diversity and Composition

• A diverse gut microbiome tends to be associated with better weight control, as diversity often means a healthy balance of bacteria that can counterbalance each other. Lower diversity is linked to weight gain and obesity, partly because a less varied microbiome may mean a higher proportion of bacteria associated with calorie absorption and fat storage.

How to Promote a Weight-Friendly Gut Microbiome

• A high-fibre diet (vegetables, fruits, whole grains)
• Fermented foods (yogurt, kefir, sauerkraut) to introduce probiotics
• Prebiotics (like garlic, onions, asparagus) to nourish healthy bacteria
• Limiting processed and sugary foods that feed unhealthy bacteria

Each person’s gut microbiome is unique, so its effects on weight can vary from one person to the next. However, cultivating a balanced, diverse microbiome through diet and lifestyle choices can be a supportive factor in maintaining a healthy weight.