Is Your Gut Making You Fat?

Is your gut making you fat?Obesity is reaching epidemic proportions in our society today and alarmingly, the problem is only getting worse despite there being numerous diets claiming miraculous transformations after ‘only days’. These diets promise that you will never be hungry and the fat will vanish forever. However, after some initial success and hard work, people eventually pack the weight back on and generally with reinforcements!

A commonly mentioned reason for an inability to lose weight relates to one’s ‘slow metabolism’. “I have a slow metabolism and that is why it is so hard for me to lose weight!” This is a common reason used to explain our ongoing weight-loss struggle. Our thyroid gland is often blamed for this slow metabolism and for some this is certainly the case. Suffering from clinical hypothyroidism or the lesser known condition, sub-optimal thyroid disorder can slow our metabolic rate, reduce our energy and make the challenge of losing weight even harder.

Recent research has also directed attention toward the importance of the gastrointestinal tract (gut) in contributing to weight problems. More specifically, studies have shown that there is a significant difference in gut bacteria between obese and lean people and this has led to interest in to whether changing the bacteria composition of the gut (gut flora) could be a potential treatment for weight problems.

Our gut contains trillions of bacteria (known as gut flora) which are designed to enhance the overall health of our body.

More specifically, when the bacteria in our gut are in balance it improves our health in the following ways:

  • Improves digestion
  • Regulates the immune system
  • Increases the overall efficiency of the body
  • Crowds out harmful microbes
  • Produces natural antibiotic effects
  • Slows the growth of pathogens
  • Reduces the harmful effects of cholesterol
  • Studies on the relationship between gut flora and obesity have found that having too much of a particular class of gut flora known as Firmicutes and not enough Bacteroidetes leads the digestive system to more efficiently extract energy from food. This means that if we have a higher ratio of Firmicutes compared to Bacteroidetes, when we eat food, more calories are taken from it, thereby leading to the increased potential of weight gain. So even if two people eat the same amount of food and perform the same amount of exercise, the individual with more Firmicutes will likely put on more weight.

    While research in the area of gut flora and obesity is still in its infancy, some of the findings so far include:

  • Bifidobacterium species of bacteria (part of the ‘lean-enhancing’ Bacteroidetes class) has been shown to be higher in children who exhibited a normal weight at seven years than in children who became overweight.
  • Bifidobacteria levels were higher in normal-weight compared to overweight women and also in higher in women who experience less weight gain during pregnancy.
  • Having an imbalance in gut flora can contribute to inflammation which triggers the common inflammatory symptoms such as pain and swelling but can also result in insulin resistance and weight gain. Studies now consistently show that inflammation can lead to weight gain and weight gain can in turn increase inflammation. A vicious cycle is now in motion.
  • In a study by Ley and colleagues they found that sterile mice that had no gut bacteria ate a lot, but didn’t get fat, presumably because they didn’t have the bacteria to extract the full complement of calories from their food. But when the scientists transferred the bacteria from fat mice to bacteria-free mice, the mice gained weight. The results suggested there’s something about the bacterial community in the obese mice that contributes to weight gain.

  • What Affects the Composition of Gut Flora?

    There are numerous factors that can affect the composition of our gut flora and the likelihood of us having a higher proportion of Firmicutes compared to Bacteroidetes. It is suspected that genetics plays a part as we inherit bacteria from our mothers soon after birth.

    Studies have also shown that the type of birth delivery (vaginally versus caesarean section) can affect bacteria levels. Our digestive flora also changes with age and are also greatly influenced by medications such as antibiotics and anti-ulcer medications.

    The quality of our diet is also are major player when it comes to the composition of our gut flora. Reducing processed sugar, refined carbohydrates and saturated fats can positively influence our flora balance. Eating high-fibre foods that serve as prebiotics (fuel for our gut flora) is another important influence on our bacteria levels.

    While more research in this area is needed, the findings on the effect of gut flora on weight gain are certainly exciting. It is one strategy that may enhance weight-loss efforts over time (it won’t be overnight) and as a positive side effect, will likely improve overall health and well-being.