from indigenous fermented foods and human gut ... - Thapar University

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Chapter V Discussion
hypothesized, that one of the mechanisms through which lactic acid bacteria protect the host
from infections is by their ability to co-aggregate with intestinal pathogens and uropathogenic
bacteria (Reid et al., 1988; Huis in't Veld et al., 1994).
A strong inclination to auto-aggregation does not imply a strong co-aggregation
property, but it has been observed that strains with high co-aggregation ability also show high
auto-aggregation (Ehrmann et al., 2002) and our findings also support the same. However,
exceptions were noted as L. casei LAM-1, which had high auto-aggregation values, did not
co-aggregated with S. aureus but weakly with L. monocytogenes. Previous co-aggregation
studies have been limited to bacteria from human origin. Schachtsiek et al. (2004) first
reported co-aggregation of Lactobacillus coryniformis, a food or feed-associated bacterium,
with pathogens. L. coryniformis was able to coaggregate with E. coli K88, Campylobacter
jejuni and Campylobacter coli, but not with S. typhimurium, Clostridium perfringens and L.
monocytogenes. In this study, the L casei strains from food origin was able to co-aggregate
with human pathogens (L. monocytogenes, S. aureus, enterotoxigenic E. coli and S.
typhimurium) the co-aggregation derived was higher degree than the commercially used
probiotic strains. Strains (especially the L. casei strains because of their inherent fermentative
versatility) with this property could be of special interest, because co-aggregates may be
formed in the food matrix, and thereby prevents the entrapped pathogens from adhering to
host cells upon ingestion (Schachtsiek et al., 2004). Decreased numbers of S. aureus together
with increased numbers in Lactobacilli and Bifidobacteria in the intestinal microbiota of
infants have been associated with atopic dermatitis (Bjorksten et al., 2001; Watanabe et al.,
2003).
For these reasons, consumption of products enriched with prebiotics and probiotic
bacteria (as the strains presented in this study), may compensate the intestinal microbial