Why are probiotics relevant today?
Today humans are less exposed to bacteria in diet and environment.
- The range of traditionally- fermented/home-made food (that would have contained probiotic bacteria) is no longer eaten. Food today is more mass-produced
- Modern hygiene and cleaning practices have reduced contact with dirt and bacteria
Many aspects of modern life disrupt the intestinal bacteria and reduce their protective effect: antibiotics and other medications; poor diet; illness and infection; stress; the process of ageing.
Figure: Factors that may adversely affect the balance of the microbiota
Who might particularly benefit from a daily, quality probiotic with good scientific evidence?
- People with gut function problems - e.g. constipation, symptoms of irritable bowel syndrome. Benefits for certain probiotics have been reported associated with gut function
- People suffering stress – physical or mental. This can impair the immune response, increasing susceptibility to minor infections
- People on antibiotics - antibiotics disrupt the intestinal microbiota; diarrhoea or irritable bowel syndrome symptoms may develop
- Certain patient groups - human studies have reported benefits associated with probiotic consumption for different patient groups, e.g. patients undergoing surgery, patients with digestive and other disorders. There is emerging evidence for specific strains for specific disorders: e.g. allergy, functional bowel disorders
- Older people - As part of the ageing process, there is a change in the profile of the intestinal microbiota to one that is considered less healthy and protective
Figure: The change in the intestinal microbiota with age
Adapted from Mitsuoka (1982) Bifido Microflora 1:3-24.
Bian L et al (2011)
Effects of the continuous intake of Lactobacillus casei strain Shirota-fermented milk on risk management of long term inpatients at health service facilities for the elderly. International Journal of Probiotics & Prebiotics 6:123-132
This was an open-label study of 42 older people (average age 82 years) in a residential nursing home in Japan, investigating the effect of a six month period where the subjects drank a fermented milk drink containing 4 x 1010L. casei Shirota (LcS). Evaluation of benefit was based on comparison of pre- and post-intervention.
|Parameter||Before intake||After 3 months LcS||After 6 months LcS|
|Fever (days/week)||1.36 ± 2.18||0.83 ± 1.74 (P less than 0.5)||0.95 ± 1.58 (P less than 0.05)|
|0.50 ± 0.55||0.33 ± 0.53||0.32 ± 0.53 (P less than 0.05)|
|0.31 ± 0.52||0.15 ± 0.53||0.18 ± 0.44 (P less than 0.05)|
Faecal analysis of the subjects and staff revealed significant differences in the microbial profile: the residents had lower levels of bifidobacteria and higher levels of clostridia compared to the staff.
Following six months of probiotic (LcS) intake, there was a significant reduction in levels of Clostridium difficile for both residents and staff; the residents also showed a significant increase in bifidobacteria numbers