Probiotics for weight loss

It is well known that the immune system is our defense shield that protects the body from harmful effects from the environment. What is less known is that the bowels are the largest organ of the human immune system. Nearly 70 % of the total number of immune cells in the body are located in the walls of our bowls. That’s why a healthy intestinal microflora full of beneficial probiotics is that important. New research suggests that healthy gut bacteria, probiotics, also have a crucial role in the regulation of weight gain. Could probiotics become the new diet pill?

Researchers at the Alimentary Pharmabiotic Centre in University College Cork have discovered how gut bacteria communicate with their host to specifically regulate weight gain and serum cholesterol levels. The team led by Dr. Cormac Gahan and Dr. Susan Joyce has increased levels of a bacterial protein (bile salt hydrolase) in mice. Bile salt hydrolase is normally made by our gut bacteria and influences the chemical properties of bile acids in our gut. Bile acids are important especially for the absorption and digestion of fats, but they also regulate triglycerides, cholesterol and glucose levels.

70% of our immune cells in the body are located in the walls of our bowls.

What the team has found is that by increasing bile salt hydrolase a reduction of serum cholesterol levels and weight gain in mice occured. In other words there exists a specific mechanism by which gut bacteria influence bile acids. Since bile acids influence weight gain a healthy microflora with probiotics is crucial for weight regulation. New research is needed to investigate which probiotic strains would have the most impact on weight and cholesterol regulation.

While we are waiting for scientists to find the specific probiotic strains best for weight loss regulation, we can help ourselves and enjoy a diet rich in probiotics. Considering that probiotics are well known to boost the immune system and help digestion, regular probiotic intake will only benefit our health.

What are probiotics?

We have both ‘good’ and ‘bad’ bacteria in our bowls. Probiotics are the ‘good’ bacteria that are naturally present in our digestive system. A healthy intestinal microflora would be 85% ‘good’ bacteria and 15% ‘bad’ bacteria. Probiotics inhabit the lower parts of the small intestine and colon, where their actions contribute to the preservation of general health and well-being. They do this in several different ways:

  • They help digestion and absorption of nutrients from the intestine
  • They are involved in the synthesis of certain vitamins like certain B vitamins, vitamin K, folate,..
  • They block the growth of harmful microorganisms in the intestines
  • They help with recolonization of good bacteria after we lose a lot of good bacteria (e.g. after taking antibiotics)
  • They help digesting certain carbohydrates that can cause bloating and cramping if not digested
  • They support normal mobility of the digestive tract
  • They stimulate the intestinal immune system by impairing the growth of bacteria that cause illness

Probiotic strains

There are more than 500 different strains of probiotics present in our body. Each has different health benefits. Here are some of the most common and most researched strains that can be found in food and supplements.

  • Lactobacillus Acidophilus
    is commonly found in our guts. It is the most researched strain of probiotics with many known health benefits.
    It helps our digestion, treats diarrhea, irritable bowel syndrome (IBS) and leaky gut syndrome.
    It reduces lactose intolerance by converting lactose into lactic acid.
    It increases our absorption of calcium, B vitamins and can even improve appetite.
    It helps fight allergies and strengthens the immune system.
    It also helps against Candida Albicans infections with women.
  • Bifidobacteria
    is the most common bacteria in our intestines. It is very sensitive to antibiotics that kill bifidobacteria and is therefore good to be repopulated with a probiotic supplement after drinking antibiotics.
    It fights yeast overgrowth in our body especially Candida.
    It helps with digestion problems like constipation, irritable bowel syndrome (IBS), diarrhea and infections.
  • Lactobacillus bulgaricus –
    is found as a live culture in many yogurts.
    It has various health benefits including the regulation of triglycerides, LDL levels and total cholesterol. It also supports digestion particularly of dairy products.
  • Lactobacillus gg –
    is extremely effective in cleaning our intestines from ‘bad’ bacteria and strengthening our immune system.
  • Streptococcus thermophilus –
    is used for culturing cheese and yogurt.
    It improves digestion and enhances immunity.
    It helps in the digestion of milk by producing lactase and produces natural antibiotic chemicals that prevent infection.

Foods rich in probiotics

There are many health benefits of probiotics, not only for our digestion but for our whole body. That’s why it is important to regularly include fermented foods in our diet. Probiotics in food are almost exclusively found in fermented food. Here are some of the richest sources:


probiotic yogurtyogurt! by Robyn Lee

Traditionally yogurt was made from fermented milk with live bacteria. But nowadays not all yogurt in the shops have live probiotic cultures in them. Look out for brands that sell plain yogurt (without added fruit, cereals or similar stuff) with the label saying- live and active cultures. Usually you can even check on the label which probiotic strains have been added to the product. Avoid plain yogurt with added sugar. Check on the label if it has added sugar since even in some plain yogurts, where you don’t suspect it, sugar is added.


probiotic kefirKefir by Claudio Brisighello

Traditional kefir is full of probiotics. It’s characteristic taste comes from fermented milk and beneficial yeasts. When buying, look out for labels that state- live and active culture. Many kefir brands today don’t have probiotics in them because they are made to have the characteristic taste of kefir but without the helpful probiotics in them. Kefir can be easily made at home with a kefir starter culture.


sauerkrautSauerkraut by erik forsberg

Fermented cabbage is a very rich source of probiotics and vitamins. That’s why it’s no surprise that it is a regular food in many cultures during winter. That way the immune system is boosted the natural way when it is needed most during winter time. If you want to enjoy the benefits of sauerkraut you have to choose an unpasteurized brand since pasteurization kills all good bacteria.


pickles Making Traditionally Fermented Pickles

Fermented pickles can be a good source of probiotics if you choose or make pickles without vinegar that kills all bacteria. Since most commercial brands add vinegar and pasteurize pickles it is a better choice to make your own if you like the idea that pickles are your source of probiotics. Make them only with water and sea salt to allow natural fermentation that will produce the healthy bacteria.



Similar to sauerkraut this is a very healthy hot Korean dish. It’s main ingredient is fermented cabbage-sauerkraut. To be beneficial it must not be pasteurized but made in a traditional way.


miso soupReceta de sopa de miso by Laura Tomàs Avellana

Miso is a traditional Japanese soup from tofu and vegetable broth. It can be bought at stores, but look out for unprocessed brands to enjoy all the probiotic benefits.


tempehTempeh 2.0 by

Tempeh is made by adding a starter culture to soy beans. In the fermentation process probiotic bacteria are formed and the soy beans become a cake like texture that can be cooked, baked or eaten raw. Look out for unpasteurized brands since the pasteurization process kills all bacteria or make your own.

Kombuha tea

Kombuha is a rich and energizing drink made from the kombuha mushroom and black tea. Nowadays brands add live cultures that have been lost during production – so look out for the label sating live and active cultures! It is also full of vitamin B.


curated olives

Fermented olives with water and salt are also a rich source of probiotics. Choose green or black olives if you prefer.

Probiotic supplements

Although there are many foods with probiotics we can choose to maintain a healthy microflora of our intestines it is sometimes necessary to take supplements when the balance of the bacteria in our guts has been shifted in favor of the ‘bad’ bacteria.

This can happen after taking antibiotics who kill not only the bacteria responsible for the disease but also all the beneficial probiotics as well. Also when we have an unbalanced diet full of fatty, sugary and processed food.

Probiotics as supplements are also very useful as prevention against digestive problems and diarrhea, when you need to travel and expect a change of diet and water. Supplements are also very helpful if your looking for a certain strain of probiotic bacteria to help a specific condition.

When buying a supplement look out for these characteristics:

  • Check out which strains of probiotic bacteria are included
  • Look out for a product with a long experation date ahead
  • Buy a product that doesn’t need refrigeration for easier use
  • It has to state that it is resistant to stomach acids, so the bacteria won’t be killed before reaching the small intestines

Boosting the effect of probiotics- PREbiotics

Probiotic bacteria have to feed on something to live and reproduce in the intestines. There are certain foods that feed probiotic bacteria and help them to thrive. They are called prebiotics. If you are taking probiotics or eating probiotic rich food it is a good idea to combine them with prebiotics. Prebiotics are found in many  foods but rich sources include bananas, whole grains, honey, garlic and onions. Two to four servings of these prebiotic-rich foods a day will help make your intestinal microflora thrive.

Although modern science hasn’t researched probiotics for a long time it is clear that they are key elements to maintain our digestive and immune system healthy. The future will bring new uses of probiotics including very promising results on the field of weight loss. As scientist find specific bacteria strains for specific conditions, probiotics with their wide spectrum of health benefits will become the new vitamins and diet pills. In the meantime we can enjoy and include healthy fermented food into our diets to boost our health.