What is Lactobacillus? What is Lactobacillus found in?

The World Health Organization (WHO) definition of probiotics is as follows: “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host”.

Lactobacillus refers to a group of rod-shaped, gram-positive, non-spore-forming bacteria of the family Lactobacillaceae. Lactobacillus are characterised by their ability to produce lactic acid as a by-product of glucose metabolism. It does this by producing an enzyme called lactase. Lactase breaks down lactose, a sugar found in milk, into lactic acid.

What are the benefits of Lactobacillus?

Lactobacillus casei: Gut health and Rheumatoid Arthritis

The Lactobacillus casei group are some of the most widely researched and applied probiotic species of lactobacilli including L. casei, L. paracasei, and L. rhamnosus. Commercially, they are used to ferment dairy products, often producing foods with improved flavour and texture.

Probiotics such as L. casei are generally considered helpful in regulating the digestive system. There have been many promising studies involving L. casei. Researchers in a trial, studied a probiotic drink containing L. casei, L. bulgaricus, and S. thermophiles. They concluded that it may reduce the incidence of antibiotic-associated diarrhoea and C. difficile-associated diarrhoea [i]. Researchers for a 2014 clinical trial found that L. casei supplements could help alleviate symptoms and improve inflammation in women with Rheumatoid Arthritis [ii].

Lactobacillus rhamnosus: Allergy relief, gut health, candida support, pregnancy and children's health

Lacticaseibacillus rhamnosus is a bacterium that originally was considered to be a subspecies of L. casei, but genetic research found it to be a separate species in the L. casei clade. Rhamnosus is a type of bacteria found naturally in your intestines.

A review of 12 studies involving 1,499 people found that supplementing with L. rhamnosus GG reduced the risk of diarrhoea from antibiotic use from 22.4% to 12.3% [iii].

Animal studies have found that L. rhamnosus strains may strengthen gut barriers, which may help relieve irritable bowel syndrome [iv]. Additionally, L. rhamnosus can prevent Candida albicans, a type of harmful bacteria, from colonising intestinal walls [v].

In terms of skin health, in a small study in 20 adults, taking an L. rhamnosus SP1 supplement helped reduce the appearance of acne [vi]. It was also seen to reduce the occurrence of other allergic manifestations in children with cow's milk allergy; including eczema, urticaria, asthma, and rhinoconjunctivitis (runny nose) [vii].

In terms of mental health, Lacticaseibacillus rhamnosus was said to significantly lower depression and anxiety scores in the postpartum period. It was thus concluded this probiotic may be useful for the prevention or treatment of symptoms of depression and anxiety postpartum [viii].

Lactobacillus plantarum: Antimicrobial properties

Lactobacillus plantarum is a species of lactic acid bacteria, which is mainly found in the fermentation of plant-derived raw materials. Lactobacillus plantarum is derived from fermentations or used to generate fermentations. It is generally associated with desirable properties in many fermented foods, and is actually added to a variety of them in order to enhance their quality or the associated health benefits. It is also found naturally in human and animal mucosa (oral cavity, gastrointestinal tract, vagina, etc.) [ix].

Plantarum exhibited anti microbial activity against staphylococcus strains which can cause disease [x]. This is because Lb. plantarum is known to produce diverse and potent bacteriocins, which are antimicrobial substances [xi].

Several studies in children with eczema found that Lactobacillus plantarum lowered the severity of eczema symptoms [xii] [xiii].

Lactobacillus plantarum is also said to have cholesterol lowering properties in both test tube and animal studies [xiv] [xv].

Lactobacillus acidophilus: Cholesterol, IBS, vaginal infections, skin health

Lactobacillus acidophilus is a type of bacteria found in your intestines. Lactobacillus acidophilus is also sometimes referred to as L. acidophilus or simply acidophilus. L. acidophilus can be found naturally in some fermented foods, including sauerkraut, miso and tempeh.

L. acidophilus may be more effective than other types of probiotics at lowering g cholesterol [xvi] [xvii]. It appears an effective method of using L. acidophilus to help increase ‘good’ cholesterol and lower blood sugar is to combine it with prebiotics (indigestible that help beneficial bacteria in the microbiome thrive). This has been demonstrated in studies using probiotics and prebiotics, both as supplements and in fermented milk drinks [xviii].

Diarrhoea may also be remedied with use of L. acidophilus, several studies have shown that probiotics like L. acidophilus may help prevent and reduce diarrhoea from various causes [xix]. In a similar fashion, it may help reduce diarrhoea associated with antibiotic use or a common infection known as Clostridium difficile [xx].

In terms of irritable bowel syndrome (IBS), L. acidophilus alone reduced abdominal pain in IBS patients and when used in conjunction another probiotic for one to two months improved bloating in several studies [xxi] [xxii].

L. acidophilus may also be used for vaginal infections. Lactobacilli are typically the most common bacteria in the vagina, in cases of certain vaginal disorders, other species of bacteria begin to outnumber lactobacilli. Studies have shown taking L. acidophilus as a probiotic supplement can help relieve vaginal infections by increasing lactobacilli in the vagina and thus improving resilience to the overgrowth of bad bacteria [xxiii] [xxiv].

Evidence suggests that probiotics can reduce the symptoms of inflammatory and allergic conditions such as eczema in both adults and children [xxv]. A study provided L. acidophilus and other probiotics to pregnant women and their infants during the first three months of life reduced the occurrence of eczema by 22% by the time the infants reached one year of age [xxvi].

Lactobacillus Lactis: Anti-ageing, immune-boosting, allergy relief, blood pressure

Lactococcus lactis is a lactic acid-producing Gram-positive species of bacteria used extensively in the production of buttermilk and cheese.

Some studies suggest this strain to have benefits regarding skin health. Ingestion of heat-killed L. lactis also maintained skin hydration and improved subjective skin elasticity in 30 middle-aged Japanese women [xxvii].

In terms of immunity, studies have found L. lactis activated certain types of immune cells known as dendritic cells (pDC), that are important for both innate and adaptive responses in the immune system. In this way this strain is said to strengthen resilience to infection [xxviii] [xxix].

Mice fed Lactococcus lactis, were seen to have a drastically improved survival rate, reduced weight loss, and reduced lung damage when exposed to various influenza virus strains.

Additionally Lactococcus lactis is seen to balance the immune system in cases of allergies via prompting Th2/ Th1 balance [xxx]. As such it was seem to significantly attenuate states of severe allergy such as atopic esophageal and bronchoalveolar eosinophilic inflammation in mice [xxxi].

Regarding cardiovascular health, L. lactis reduced blood pressure, and LDL (bad) cholesterol, and blood lipid contents in rats with high blood pressure [xxxii].

Who should take caution?

Lactobacillus is generally safe for most, but there are potential risks. These include rare cases of infection in people with weakened immune systems, the possibility of allergic reactions, and mild gastrointestinal side effects. It's important to consult with a healthcare professional before taking Lactobacillus if you have underlying health conditions or are taking medications which may interact.