The human body is teeming with bacteria. In fact, only about 40% of the total number of cells in your body are human cells. It’s no wonder then that the bacteria in your gut have such a significant influence over how you feel. In this blog post we’ll take a look at probiotics for digestive health, paying particular attention to three probiotic species that can help keep your gut in tip-top condition.

How Probiotics Support Digestion

Before we look at the benefits of specific probiotic strains, let’s quickly summarise what we mean by probiotics, and how it is that these organisms support digestive health.

The word probiotic is made up of ‘pro’ meaning ‘for’ and ‘biotic’ meaning ‘life’, and refers to the wide variety of beneficial organisms that live in the digestive tract. These probiotics form a microbiome in the gut, and the delicate balance of this microbiome influences an array of physiological activities, including:

• The production of enzymes needed to break down food and release nutrients
• The production of neurotransmitters that affect the enteric (gut) nervous system
• The synthesis of nutrients, such as vitamin B12
• Colonisation of the gut by bad bacteria and other pathogens
• The production of pro-inflammatory molecules by pathogens
• Immune system function in the gut
• Permeability of the intestines.

Together, probiotics support the proper breakdown of the foods we eat. This helps to release nutrients that themselves support digestive health, such as B vitamins that are often bound to protein in food. If we digest food properly this reduces the likelihood of undigested food lingering in the gut where it can feed pathogens like Escherichia coli and Staphylococcus aureus, leading to bacterial overgrowth.

Symptoms of bacterial overgrowth are related to inflammation, oxidative damage, and toxicity in the gut. Pathogens and the substances they produce can lead to tissue damage, immune system dysfunction, gas, cramping, constipation and diarrhea. Maintaining a healthy microbiome can keep potential pathogens in check and keep such symptoms at bay.

Factors that Affect the Microbiome and Gut Health

Many factors can affect the delicate balance of bacteria in the gut, with different effects on different species and strains of bacteria. In some cases, the microbiome may be upset by outright infection from eating or drinking contaminated food and water (such as with traveler’s diarrhea). Other factors that affect the microbiome include illness, stress, antibiotic use, aging, menstrual cycles, pregnancy, and the foods we eat.

Aging and Probiotics for Digestive Health

The diversity of the microbiome begins to decline after the age of 50, as does immune system activity. This leaves older adults increasingly susceptible to opportunistic infections as well as to poor gut health and other health concerns. Around 20% of people aged 60-80 have some degree of overgrowth of undesirable bacteria in the gut. This rises to about 40% of people over the age of 80.

How to Choose a Probiotic Supplement

When choosing a probiotic supplement, it is important to consider the factors currently affecting gut health and to understand a little about each bacterial species.

Lactobacillus species predominate in the small intestine, while Bifidobacteria are the major species in the large intestine. This means that both species need to be replenished during and after broad spectrum antibiotic use or major gastrointestinal upset. Older adults should also make sure to replenish both species to maintain microbiome diversity and immune system function.

In general, then, best practice for choosing a probiotic is to opt for a multistrain formula providing a diversity of Lactobacillus and Bifidobacteria. Be sure to choose a formula featuring bacterial species that are resistant to gastric acid, so that they survive stomach acid and reach the intestines alive and at full potency.

In terms of dose, for general maintenance of health look for a probiotic formula that has a guaranteed minimum of 10 billion colony forming units at least at the date of manufacture and at the date of expiry. If you’re experiencing a flare-up of gastrointestinal symptoms or are replenishing your microbiome after illness or antibiotic use, look for critical care probiotics providing at least 30 billion colony forming units, such as Natren’s Healthy Trinity.

And, finally, consider using a formula that features some of the most rigorously researched probiotics that have demonstrated significant health benefits time and again. Three top species to watch out for include:

1. L. acidophilus – produces amylase and lactase to support the digestion of lactose and carbohydrates in general. Can also improve resistance against methicillin resistant Staphylococcus aureus (MRSA) and other opportunistic pathogens.
2. L. bulgaricus – also supports the digestion of lactose and enhances immune response in the gut, helping to fight off infection (especially important for older adults)
3. B. bifidum – essential for gut immune function and particularly important to replenish after antibiotic use. Shown to help alleviate gastrointestinal symptoms including diarrhea during periods of stress, such as final exams!

These three probiotic strains not only have impressive individual benefits, they also interact with each other to influence gut health and immune function. For instance, a meta-analysis of twelve studies found that a combination of L. acidophilus and B. bifidum significantly reduces the risk of traveller’s diarrhoea. And, in another study, B. bifidum, L. acidophilus, and L. bulgaricus were among the probiotic strains identified as having the greatest benefits for taste disturbance, constipation, and nausea and vomiting when trying to eradicate infection with Helicobacter pylori.

So, if you’re looking for the best probiotics for digestive health, read the label and make sure to get a multistrain formula including this top trio!

References

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Jandu, N., Zeng, Z.J., Johnson-Henry, K.C., & Sherman, P.M. (2009). Probiotics prevent enterohaemorrhagic Escherichia coli O157:H7-mediated inhibition of interferon-gamma-induced tyrosine phosphorylation of STAT-1. Microbiology, Feb;155(Pt 2):531-40.

Kovalenko, N.K., Poltavskaia, O.A., Zelenaia, L.B. (2012). Bifidobacterial species composition of digestive tract of people of different age groups. Mikrobiol Z. Jan-Feb;74(1):8-13.

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