Prajapati and Senan

genesȱ conferringȱ physiologicalȱ benefitsȱ likeȱ immunostimulation,ȱ

cholesterol reduction, and folate production. Thus, through trait and

gene matching, the study established that the strain possessed the genetic

arsenal required to adapt to the gut milieu. (Senan et al., 2014a).

Genome-scale analysis of niche-based stress responsive genes in

Lactobacillus helveticusstrains

Next generation sequencing technologies with advanced bioinformatic

tools present a unique opportunity to compare genomes from diverse

niches.ȱWeȱattemptedȱtoȱcompareȱtheȱstress-responsiveȱgenesȱofȱaȱpotentialȱ

probiotic strain, Lactobacillus helveticus MTCC 5463, and a cheese starter

strain, Lactobacillus helveticus DPC 4571, from a gut and dairy niche,

respectively. The MTCC 5463 genome carried multiple orthologs of

genes governing stress responses, whereas the DPC 4571 genome lacked

in the number of major stress response proteins. The absence of the bile

salt hydrolase gene in DPC 4571 and its presence in MTCC 5463 clearly

indicated niche adaptation. Further, MTCC 5463 carried higher copy

numbers of genes contributing towards heat, cold, osmotic, and oxidative

stress resistance as compared with DPC 4571. Through comparative

genomics, we could thus identify stress-responsive gene sets required to

adapt to gut and dairy niches (Senan et al., 2014b) .

Human clinical trials:

Live lactobacilli or their metabolites have known to lower the blood

cholesterol through assimilation of dietary cholesterol and indirectly via

deconjugation of bile salts. After in vitro testing, we conducted feeding

trial of acidophilus milk on 27 human volunteers of normal as well as

hyperlipemia groups. Feeding of acidophilus milk resulted in reduction of

total cholesterol by 11.7, 21.0, 12.4 and 16.4 % in volunteer group A1 (40-

60 years), C2 (200-220 mg/dl initial cholesterol), C3 (220-250 mg/dl initial

cholesterol) and H1 (normal health), respectively (Ashar and Prajapati,

1999).ȱTheȱfeedingȱfavourablyȱaffectedȱtotalȱserumȱcholesterolȱandȱLDL/

HDLȱorȱTotal/HDLȱratios.ȱOverall,ȱtheȱfeedingȱwasȱmostȱbeneficialȱtoȱtheȱ

volunteersȱofȱ40-60ȱyears,ȱwhichȱhaveȱtheȱhighestȱriskȱofȱheartȱattack.ȱ

Encouraged by the results of the above mentioned investigation we

conductedȱaȱclinicalȱtrialȱtoȱstudyȱtheȱeffectȱofȱconsumptionȱofȱmilkȱbasedȱ

synbiotic product on the intestinal well being and humoral immune

response in health human subjects. The intervention study could not

confirmȱ aȱ beneficialȱ effectȱ ofȱ probioticsȱ onȱ healthȱ adultsȱ inȱ mattersȱ ofȱ

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