| Study |
Probiotic used for study |
Conclusion |
Ref |
| In vivo human studies |
| Undertook 9 healthy volunteers and they undergo intervention with standard yoghurt or probiotic yoghurt and then they were incubated with HT-29 clone19A human colon tumor cells from their collected fecal water after dietary intervention. Then they underwent DNA damage studies in colon cells |
L.acidophilus
145 andB. longum 913 |
Probiotic yoghurt intervention decreased DNA damage in colon cells,in comparison to standard yoghurt |
[146] |
| Conducted on 38 healthy male subjects who undergo double-blind, randomized, two period crossover, placebo controlled study and they supplemented probiotic bacteria on daily dose for 4 weeks then they evaluated levels of harmful carcinogenic bacterial enzymes. |
L. rhamnosus LC705 and
P. freudenreichii ssp. shermanii JS |
Probiotic administration significantly decreases the β-glucosidase activity with increased counts of Propionibacteria. |
[147] |
| Performed cross over,placebo controlled study with7 healthy subjects (1male and 6 females).Each volunteeris supplemented with 100g/day of LKM512 yogurt or placebo for 2 weeks.Then they evaluated for faecal mutagenicity. |
Bifidobacteriumlactis LKM512 |
Probiotic yoghurt consumption significantly reduces the faecal mutagenicity in all 7 healthy subjects when compared to the placebo treatment |
[148] |
| Undertook 11 subjects for their study and as a part of their diet, they’re given with fried beef patties for 3 days daily twice. In phase 1 they provided with ordinary Lactococcus fermented milk and thereafter in phase 2 they supplemented fermented milk containing Lactobacillus acidophilus and they determined excretion of urinary and fecal mutagenic activity. |
L. acidophilus |
Upon consumption of Lactobacillus acidophilus decreased mutagenic excretion was observed. |
[149] |
| Conducted a clinical study with 20 healthy subjects and they undergo consumption of probiotic mix product containing both Lactobacillus rhamnosusLC-705 and Propionibacteriumfereudenreichii JS and they evaluated aflatoxin B1 level in fecal samples. |
L.rhamnosus LC-705 P. fereudenreichii JS |
Probiotic mixture successfully decreased the aflatoxin levels in faecal samples. |
[150] |
| Undergone 3 week of study with nine healthy volunteers and they supplemented with fermented dairy product before, during, after containing a probiotic mix of 4 cultures Finally, they assessed for
fecal concentration of azoreductase, nitroreductase, β-glucuronidase. which are involved in colon risk |
L.acidophilus,
B. bifidum,
Streptococcus (Lactococcus) lactis,
L. lactis subsp. Cremoris |
After 3 weeks of fermented dairy product consumption, there is a decreased nitroreductase activity is noted, Howeverno changes is observed in others during experiment |
[151] |
| Undertook 398 subjects and they divided randomly into 4 groups, then administered with Lactobacillus casei, wheat bran,both or neither.At the end of 4 years they undergo a process of colonoscopy for the presence or absence of new colonic polyps. |
L.casei |
Among all treatments,probiotic treatment was found to significantly decreases atypical colonic polyps. |
[152] |
|
In vivo animal model studies |
| Undertook F344 male rats and divided into 4 groups, thensupplemented with:
Group 1: 20% water.
Group 2:supplemented with 30% non-fermented skim milk.
Group 3: supplemented with 30% Bifidobacteriumanimalis
DN-173010-FM.
Group 4: supplemented with 30% Streptococcus thermophilus DN-001 158-FM
After that, during 1 week they were provided experimental diet followed by HAA (heterocyclic aromatic amines) consumption for 7-8 weeks and then they evaluated aberrant crypt assessment, measuring HAA metabolism by enzymatic dosages, fecal mutagenicity by using 3d test and colonic lesion damage by comet assay |
B.animalis DN-173 010-FM.
Streptococcus thermophilus DN-001 158-FM |
Aberrant crypts incidence was decreased compared to control diet.
-Decreased HAA metabolism was noticed and reduced colonic DNA lesions, feacal mutagenicity was also noticed. |
[153] |
| Undertook F344 male rats and they divided into 3 groups
Group 1:
Fed with low fiber and high fat diet
Group 2:Fed with low fiber and high fat diet+DMH (1, 2-dimethylhydrazine dihydrochloride) treated
Group 3: Fed with low fiber and high fat diet+DMH+probiotic (3 × 108cfu/1.3g). Then throughout the experiment they maintain the diet and then they analyzed for a count of aberrant crypt foci and antioxidant system |
Bacillus polyfermenticus |
Upon probiotic treatment aberrant crypt foci numberwas significantly decreased when compared to DMH treated group and also exhibited a protective effect on colon carcinogenesisprocess and on antioxidative system |
[154] |
| Undertook 20 mice and they randomly divided into 4 groups
Group 1: (Negativecontrol), Mice given normal physiological
saline (0.9% NaCl).
Group 2: Mice supplemented with the
Lactobacillus rhamnosus IMC501
Group 3: (Posititve control), Mice given with PhIP(2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine- a food mutagen)+ physiological saline.
Group 4: Lactobacillus rhamnosus IMC501 + PhIP.
Afterwards they undergone comet assay for to evaluate DNA demage in colon |
L.rhamnosus IMC501 |
Lactobacillus rhamnosus
IMC501 exhibit
protective effect on
PhIP-induced DNA damage in colon cells |
[155] |
| Undertook 24 male wistar rats for a 32 week study and divided them randomly into 5 groups.
Group1: (control group) supplemented with buffalo milk(BM)
Group2: (DMH control group)Injected with DMH.
Group3: Administered with BM + PXC(piroxicam) in DMH.
Group4:Supplemented with probiotic dahi+DMH
Group5:Supplemented with probiotic dahi+PXC+DMH.
Afterwards rats were sacrificed at 8,16 and 32 week and then evaluated for
Thiobarbituric acid reactive
substances(TBARS)+ glutathione-S-transferase activity. |
L.acidophilus LaVK2,
L.plantarum Lp9. |
Probiotic
Dahi that is administered individually or in combination
with PXC to experimental rats possesses a potent
protective effect against DMH-induced colorectal
carcinogenesis
by lowering the levels of TBARS, faecal
β-glucuronidase and by enhancing the activity GST in liver and colorectal tissues |
[156] |
| Gnotobiotic studies
Gnotobiotic animals is an animal which contain only known strains of bacteria and other certain microorganisms. This term also includes germ- free animals because of the known status of their microbial communities.
Gnotobiotic animals are born in sterile conditions which may include delivery from the mother through caesarean method and then transferred the new-born to an environment where everything is sterile such as air, water and food in a microbiologically controlled sterile environment. Such animals are used by the researchers’ and expose solely to microorganism interest of their study [157,158] |
|
Undertook Germ free Lister Hooded ratsassociated with human faecal flora(gnotobiotic) and they supplemented with probiotic preperations and they analysed for activities of β-glucosidase and β-glucuronidase. |
Lactobacillus acidophilusNCFM, Bifidobacteriurnadolescentis 2204 |
Probiotic treatement successfully suppressed the activities of β-glucosidase and β-glucuronidase in colon. |
[159] |
| Undertook 32 Germ free male fischer rats inoculated with human intestinal microflora(gnotobiotic) and they supplemented milk fermented with probiotic afterwards they determine composition and metabolic activities(beta-glucuronidase)of intestinal microbiota |
Lactobacillus casei |
High number of Bifidobacteria in feacal contentand low activity of beta-glucuronidase is observed. |
[160] |
|
Simulator of the Human Intestinal Microbial Ecosystem studies(SHIME)
Simulator of the Human Intestinal Microbial Ecosystem (SHIME) is a computerized controlled device used as a scientifically validated model to study nutrition studies, enzymatic studies and microbial parameters in the GI tract and also it is useful to analyse the intestinal microbial community composition[161-164]. |
| Undertaken microbial suspension of Lactobacillus reuteri in a batch culture mode with the help of SHIME(Simulator of the Human Intestinal Microbial Ecosystem) to asses the protective effect of the bile salt hydrolase-active L. reuteri against bile salt cytotoxicity. |
Lactobacillus reuteri |
It prepeciptate the deconjugated bile salts and adsorbed on the surface of bacterium by physical binding and makes the harmful bile salts less bioavailability, Hence protective in nature against colon cancer risk |
[165] |
| Cell line based study |
| Performed experiment by using
probiotics on two different cancer cell lines-Colon (HI-29) and PANC-1(Pancreas). |
L. rhamnosus ATCC 9595 |
Probiotic treatment decreases the cancer growth successfully in cell lines |
[166] |
