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What IS Yakult??

February 4, 2019

What on earth IS Yakult?


Yakult is labelled as a ‘probiotic drink’. It comes in a 65ml bottle and contains 6.5 billion of the live bacteria strain; Lactobacillus casei Shirota.

Per 65ml bottle, Yakult (original) has: 50 calories, 0.8g protein, <0.1g fat (<0.1g saturated fat), 11.5g carbohydrate (11.2g sugars), 10.1mg sodium.

What is a probiotic?

The World Health Organisation defines probiotics as ‘live microorganisms which when administered in adequate amounts confer a health benefit on the host’.

Further to this Mack (2005) states: ‘while it is clear that antibiotics are chemicals that are used against bacteria, probiotics are not chemicals that are used for the benefit ofbacteria, but rather describe microorganisms administered orally’.

The World Health Organisation says that in order for a product to be labelled as a ‘probiotic’, scientific evidence for the health benefit would have to be documented.

Scientific evidence?

Currently, Yakult (or the particular strain of bacteria used in Yakult) tends to be promoted, or associated with, an effect on immune function and gut health/function.

There are some studies to suggest that the particular bacteria strain in Yakult may confer an immune system benefit (eg reduced frequency of upper respiratory tract infections) (Gleeson et al, 2011) and may assist those with constipation (eg softening stools) (Koebnick, 2003), antibiotic-associated diarrhea (eg prevention or reducing severity or length of time with diarrhea) (Issa & Moucari, 2014) and irritable bowel syndrome (eg a reduction in symptoms) (Thijssen et al, 2011). In the case of antibiotic-associated diarrhea, Issa & Moucari (2014) call for probiotic use only on a case-by-case basis.

It is very important to remember that Yakult (or the particular strain Lactobacillus casei Shirota) has never been approved for the treatment of a specific health problem.

It is still a relatively new phenomenon to have products on the supermarket shelf that can provide a concentrated source of probiotics on a daily basis.

We certainly need more literature showing evidence for specificity around:
– the type of bacteria strain best for individual conditions
– the dosage required for optimal effect
– the duration of use for optimal effect
– the timing of use for optimal effect
– the indications and contra-indications for use (eg who would most benefit and who is most at risk)

My opinion on Yakult?
Yakult is best defined as a supplement rather than a food.

It is best to talk to a health professional (GP or dietitian) about the appropriateness of trialling Yakult for the purpose of alleviating constipation, antibiotic-associated diarrhea or IBS as there may be underlying medical conditions involved, or a better or more effective way to manage these conditions. Immune compromised individuals should certainly not be using probiotics and should speak with their GP or specialist.

Probiotics for enhanced immune function and reduced incidence of upper respiratory tract infections is useful to talk about in another blog post – especially in the context of travelling athletes or hard training athletes in the winter months! (keep your eyes PEELED for this one).

Keep in mind that each bottle of Yakult contains 2.5 tsp of sugar. So, even if using probiotics, there might be better ways to do it.

Ps: Taste – I like it. It tastes like a shot of sugar 😉





Gleeson, M., Bishop, N.C., Oliverira, M. & Tauler, P. (2011). Daily probiotic’s (Lactobacillus casei Shirota) reduction of infection incidence in athletes. Int J Sport Nutr Exerc Metab, 21(1): 55-64.

Koebnick, C., Wagner, I., Leitzmann, P., Stern, U. & Zunft, H. J. (2003). Probiotic beverage containing Lactobacillus casei Shirota improves gastrointestinal symptoms in patients with chronic constipation. Can J Gastroenterol, 17(11): 655-9.

Mack, D. R. (2005). Probiotics, Can Fam Physician, 51(11): 1455-1457.

Thijssen, A., Jonkers, D., Vankerckhoven, V., Goossens, H., Winkens, B., Clemens, C. H. & Masclee, A. (2011). A randomised, placebo controlled, double blind study to assess the efficacy of a probiotic dairy product containing lactobacillus casei shirota on symptoms in irritable bowel syndromw. Gastroenterology, 140(5): S-609.




Please note: I am not sponsored by Yakult (nor any food company OR food product OR supplement for that matter). Where possible, I don’t accept freebies either (sometimes they just turn up, however! In which case I eat them (of course), but only speak about them if I feel I have something relevant or useful to say.

This article contains general information. Your nutrition needs are highly individual. If you have medical conditions, medications, allergies or intolerances, it is important you seek individualised advice from an Accredited Practising Dietitian or Accredited Sports Dietitian rather than follow generalised information. You can find an Accredited Sports Dietitian near you here.

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