Forefront of lactic acid bacteria research

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What is the immune system? Relationship between lactic acid bacteria and people’s immune strength Function of NK cells Findings from 1073R-1 lactic acid bacteria research

Findings from 1073R-1 lactic acid bacteria research(6)

Yogurt containing 1073R-1 lactic acid bacteria has been confirmed to potentially suppress the decline in immunity (NK activity) temporarily and maintain good physical conditions in subjects at high risk of immune dysfunction (human study conducted in male university track-and-field athletes (healthy individuals) aged 18 to 25 in 2012).

This study demonstrated that it is effective in maintaining normal immune function even in people at high risk of weakened immune function. In addition, ingestion of group consuming yogurt containing 1073R-1 lactic acid bacteria is thought to be effective in maintaining systemic homeostasis and good physical condition through suppressing the temporary decline of intestinal function and the abnormal amino acid metabolism. This result was found for the first time thanks to the fact that 6.6 mg of R-1 EPS was ingested, twice as much as in previous studies.

Risk of weakened immune function

Decline in immune function is thought to increase the risk of developing a variety of infectious diseases*1 and to be related to poor physical and psychological conditions*2. While there are various causes of the decline in immune function such as aging, it is also known that irregular lifestyles and strenuous exercise are risk factors. It is also reported that strenuous exercise may damage the intestinal tract and impair protein digestion and absorption*3. In order for athletes to stay in good physical condition, it is critical to maintain normal immune function and not to allow blood levels of essential amino acids to decrease, as these help repair post-training muscle damage*4.

  • * 1Source： Brolinson PG, et al. Clin Sports Med 26: 311-319, 2007.

  • * 2Source： Agans RT, et al. Front Nutr 7: 70, 2020.

  • * 3Source： van Wijck K, et al. Am J Physiol Regul Integr Comp Physiol 304: R356-361, 2013.

  • * 4Source： Waskiw-Ford M, et al. Nutrients 12: 1061, 2020.

Fluctuations in NK activity and blood levels of amino acids

18 male long-distance runners and 13 male throwers in a university track-and-field club were randomly divided into two groups without unbalanced distribution, one of which received group consuming yogurt containing 1073R-1 lactic acid bacteria (containing 6.6 mg of R-1 EPS) and the other received placebo (acidic dairy drink) for two weeks. The athletes were subjected to strenuous exercise in a weeklong training camp during those two weeks. The primary endpoint of this study was NK activity.

Fluctuations in NK activity (Figure 1)

Fluctuations in blood levels of amino acids (Figure 2)

Subject
pool		 Male athletes belonging to a university track-and-field club (healthy long-distance runners and throwers aged 18 to 25)
Number of subjects 31
Amount Group consuming yogurt containing 1073R-1 lactic acid bacteria: 112 ml x 2/day
*Consuming two bottles of yogurt containing 3.3 mg of R-1 EPS (6.6 mg) every day
Group consuming acidic dairy beverage (placebo group): 112 ml x 2/day
Period of consumption 2 weeks (including 1 week of training camp)
Study
period		 2012

(Source: Takayuki TOSHIMITSU et al. Japanese Journal of Physical Fitness and Sports Medicine. 2023;72(2):161-72.)

The results showed that in the yogurt group (n=16) compared to the placebo group (n=15),

  1. (1)
    the decrease in NK activity induced by strenuous exercise was significantly suppressed and the decline in immune function was prevented (Figure 1), and similar effects were observed for other immunological indicators, too; and
  2. (2)
    the decrease in blood levels of essential amino acids and branched-chain amino acids induced by strenuous exercise was suppressed and the decline in physical condition was prevented (Figure 2).

These results demonstrated that ingestion of group consuming yogurt containing 1073R-1 lactic acid bacteria (containing 6.6 mg of R-1 EPS) suppressed the temporary decline in immune function induced by strenuous exercise. In addition, ingestion of the yogurt is expected to suppress the decline in intestinal function induced by strenuous exercise and maintain normal blood levels of amino acids, helping to maintain good physical condition.