A number of variations in the composition of the gut microbiota in older adults, compared to younger adults, has been reported. Typically, the gut microbiota changes to one that seems to be less healthy and less protective. Research using bacterial isolation techniques has shown that microbial diversity tends to be lower in older adults when compared to younger adults and that number and diversity of bifidobacteria decrease (Duncan & Flint, 2013), (Claesson et al 2011).
It is suggested that age-related changes of the gut microbiota alter the gut environment to make it more favourable for growth of pathogens, with an increased associated disease risk in the elderly (Hopkins & Macfarlane, 2002).
It therefore seems logical to investigate the role probiotics can play in this population group, particularly in regards to maintaining or improving microbial diversity, as well as reducing diseases often associated with decreased microbial diversity.
Several studies have been conducted using Lactobacillus casei Shirota in older subjects, particularly in a residential setting, investigating the effects long term intake can have on microbial diversity and bowel health, (Van Den Nieuwboer et al. 2015, Vignati et al. 2014), general health (Nagata et al. 2016, Bian et al. 2011 (as described below)), infectious diarrhoea (Wright et al. 2014, Pirker et al. 2013, Lewis et al. 2009), norovirus (Nagata et al. 2011), and immune health (Dong et al. 2013, Van Puyenbroek et al. 2012).
Study: Older People
Effects on risk management of residents at an elderly care facility - Bian et al (2011) International Journal of Probiotics & Prebiotics 6:123-132
Method: In an open-label study, 42 older people (average age 82 years) in a residential nursing home in Japan consumed a drink containing L.casei Shirota (4 x 1010 CFU) daily for 6-months. Residents were monitored over the intervention period for incidence of fever, constipation, and diarrhoea. Fecal samples were also collected pre and post intervention.
Results: A reduction in number of days that residents had a fever, constpation or diarrhoea was observed (data presented in the table).
Faecal analysis: Pre-intervention, 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.