What You Should Know About Short-chain Fatty Acids & Weight Loss

The good and friendly bacteria in your gut are responsible for the production of short-chain fatty acids.

It is important to note that these short-chain fatty acids are the primary source of nutrition for your colon cells.

Short-chain fatty acids also play vital roles in health and disease. They have therapeutic effects against inflammatory diseases, obesity, type 2 diabetes, heart disease, etc. (1)

Here, we will discuss the effects of short-chain fatty acids on health, and also how it influences weight loss.

What are short-chain fatty acids?

Short-chain fatty acids are fatty acids that have less than 6 carbon atoms (2). They are products of fiber fermentation. The friendly bacteria in your gut ferment the fiber in your colon, resulting in the production of short-chain fatty acids.

These short-chain fatty acids are the major source of energy for your colon cells. This explains why they are so important to your colon health (1).

Short-chain fatty acids also play other roles in your body, especially when they are in excess. For instance, they can provide your body with up to 10% of its daily calorie needs (2).

They are also involved in fat and carb metabolism (3).

Most of the short-chain fatty acids in your body include:

  • Acetate
  • Propionate
  • Acetate

Propionate plays an important role in glucose production (in the liver). On the other hand, butyrate and acetate are incorporated into cholesterol and other fatty acids (4).

The precise amount of short-chain fatty acids in your body system is affected by several factors. These include the population of microorganisms in your gut, the source of food, and how long it takes for food to move through your gut (5).

Foods that contain short-chain fatty acids

Short-chain fatty acids are provided by such foods as vegetables, fruits, and legumes, as well as other fiber-rich foods (6).

A study involving 153 participants found that consumption of plant foods was associated with an increase in the amount of short-chain fatty acids (7).

It is important to note, though, that the type of fiber and the amount of fiber that you eat determines the kind of bacteria that you have in your gut. This in turn affects the kind of short-chain fatty acids produced (8).

For instance, several studies have shown that when you eat more fiber, the amount of butyrate produced by your body will increase. Conversely, decreasing your fiber intake results in a lowered production of fiber (9).

Fibers that contribute best to short-chain fatty acid production include (10, 11):

  • Inulin: Inulin can be gotten from garlic, artichokes, onions, leeks, asparagus, rye, and wheat.
  • Fructooligosaccharides: These are present in various vegetables and fruits, such as garlic, bananas, asparagus, and onions.
  • Pectin: Foods that are rich in pectin include carrots, apples, oranges, apricots, etc.
  • Resistant starch: Resistant starch can be gotten from barley, grains, rice, green bananas, beans, potatoes, and legumes.
  • Guar gum: You can extract guar gum from guar beans, and guar beans are legumes.
  • Arabinoxylan: They are present in cereal grains. It is very common in wheat bran and makes up to 70% of its total fiber content.

Some kinds of butter, cow’s milk, and cheese also contain butyrate but in small amounts.

Short-chain fatty acids and digestive problems

Short-chain fatty acids are beneficial against some digestive conditions. Butyrate, for instance, has anti-inflammatory effects (12).

Diarrhea

The bacteria in your gut converts pectin and starch to short-chain fatty acids. Studies have shown that eating short-chain fatty acids is effective against diarrhea in children (13, 14).

Inflammatory bowel disease

Crohn’s disease and inflammatory bowel disease are the primary types of inflammatory bowel disease. Both diseases share a common characteristic – chronic bowel inflammation.

Butyrate has anti-inflammatory properties which make it effective in the treatment of these conditions.

Rodent studies have shown that butyrate supplements are effective against bowel inflammation. Similar benefits are also offered by acetate supplements. What’s more? Studies have also associated low levels of short-chain fatty acids with complications such as ulcerative colitis (15, 16).

Studies involving human subjects have shown short-chain fatty acids like butyrate are effective against Crohn’s disease and ulcerative colitis (17, 18, 19, 20).

Another study involving 22 ulcerative colitis patients found that eating 60g of oat bran daily for 3 months improved the symptoms of this condition (17).

Also, another study found that symptoms of Crohn’s disease were improved when patients took butyrate supplements. At least 53% of the patients experienced remission (18).

Patients with ulcerative colitis experienced a 13% reduction in symptoms after receiving an enema of short-chain fatty acids twice daily for 6 weeks (21).

What effect do short-chain fatty acids have on colon cancer?

Short-chain fatty acids play important roles in cancer prevention and treatment. Their therapeutic effect is mostly seen in colon cancer (22, 23, 24).

Results from laboratory studies suggest that butyrate maintains the health of colon cells, prevents tumor cells from growing, and promotes the destruction of cancer cells in the colon (24, 25, 26, 27).

How this happens is not fully understood (28, 29, 30).

A couple of observational studies suggest that high-fiber diets may reduce colon cancer risk. It is believed that the production of short-chain fatty acids may be a contributing factor (28, 30).

Several animal studies have also shown that a high-fiber diet reduces the risk of colon cancer (31, 32).

A particular study found that mice fed with a high-fiber diet had 75% fewer tumors than mice who were not. The former group also had butyrate-producing bacteria in their gut (33).

It is important to note that the high-fiber diet, on its own did not affect colon cancer. The effect was only pronounced in animals who had butyrate-producing bacteria in their gut (33). Also, a low-fiber diet was ineffective, even when the animal had butyrate-producing bacteria in its gut.

This implies that the anti-cancer benefits are gotten only when a high-fiber diet is combined with the appropriate gut bacteria.

Results obtained from human studies are mixed. While some studies established a link between high-fiber diets and a low risk of cancer, others found no association (34, 35, 36, 37).

What effect do short-chain fatty acids have on diabetes?

A study review reported that butyrate was effective against animal and human models of type 2 diabetes (38).

Also, this review suggested that there might be an imbalance in the population of gut flora in diabetic patients (38, 39).

Short-chain fatty acids increase the activities of enzymes in the muscle and liver tissue, thus enhancing blood sugar control (40, 41, 42).

Animal studies have shown that supplementation with propionate and acetate supplements improved the levels of blood sugar in normal rats and diabetic mice (43, 44, 45).

There aren’t many studies, and the results are mixed.

In one of the studies, propionate supplements caused a reduction in blood sugar levels. However, another study found that supplementing with short-chain fatty acids did not affect blood sugar in healthy people (46, 47).

Several human studies have established a link between intake of fermentable fiber and effective control of blood sugar as well as insulin sensitivity (48, 49).

It is important to note that these effects are readily observed in insulin-resistant or overweight individuals (46, 47, 50).

Do short-chain fatty acids promote weight loss?

Gut flora has some influence over energy regulation and nutrient absorption. This, in turn, influences the development of obesity (51, 52).

Some studies have shown that short-chain fatty acids promote fat burning and also decrease fat storage (8.

This reduces the population of free fatty acids in the blood, which may in turn prevent weight gain (40, 53, 54, 55).

This effect has been investigated by a couple of animal studies. Obese mice who were treated with butyrate for 5 weeks, lost about 10.2% of their body weight. Fat percentage was reduced by 10%. Acetate supplements caused a drastic reduction in fat storage in rats (40, 56).

It is important to note that most of the studies linking short-chain fatty acids to weight loss are test-tube or animal-based.

Is taking supplements a healthy practice?

Well, most short-chain fatty acid supplements occur in the form of butyric acid salts.

They are commonly referred to as potassium, sodium, magnesium, or calcium butyrate. You can purchase them over-the-counter or online.

But then, supplements may not be the healthiest way to boost your levels of short-chain fatty acids. most butyrate acids are absorbed in the small intestine, meaning that your colon cells won’t get any of the benefits.

Also, there isn’t much scientific evidence supporting its effectiveness.

Butyrate from fermented fiber reaches the colon in good amounts, as such, you’re better off increasing your consumption of high-fiber foods. This is a better way to boost your short-chain fatty acid levels.