Mucosal adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG in the human colonic mucosa: A proof-of-concept study

• Published in: World journal of gastroenterology : WJG Vol. 24; no. 41; pp. 4652 - 4662
• Main Authors: Pagnini, Cristiano, Corleto, Vito Domenico, Martorelli, Michela, Lanini, Claudio, D’Ambra, Giancarlo, Giulio, Emilio Di, Fave, Gianfranco Delle
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 07.11.2018
• Subjects: Adhesiveness; Basic Study; Biopsy; Colitis, Ulcerative - diet therapy; Colitis, Ulcerative - microbiology; Colitis, Ulcerative - pathology; Colon - microbiology; Colon - pathology; Colonoscopy; Cytokines - metabolism; DNA, Bacterial - isolation & purification; Feasibility Studies; Gastrointestinal Microbiome - genetics; Humans; Intestinal Mucosa - microbiology; Intestinal Mucosa - pathology; Lactobacillus rhamnosus; Probiotics - administration & dosage; Treatment Outcome; Probiotic; Cytokines; Adhesion; Lactobacillus rhamnosus GG; Ulcerative colitis
• ISSN: 1007-9327; 2219-2840; 2219-2840
• DOI: 10.3748/wjg.v24.i41.4652

To investigate the adhesion and anti-inflammatory effects of GG (LGG) in the colonic mucosa of healthy and ulcerative colitis (UC) patients, both and in an organ culture model. For the experiment, a total of 98 patients (68 UC patients and 30 normal subjects) were included. Endoscopic biopsies were collected and incubated with and without LGG or LGG-conditioned media to evaluate the mucosal adhesion and anti-inflammatory effects [reduction of tumor necrosis factor alpha (TNFα) and interleukin (IL)-17 expression] of the bacteria, and extraction of DNA and RNA for quantification by real-time (RT)-PCR occurred after the incubation. A dose-response study was performed by incubating biopsies at "regular", double and 5 times higher doses of LGG. For the experiment, a total of 42 patients (20 UC patients and 22 normal controls) were included. Biopsies were taken from the colons of normal subjects who consumed a commercial formulation of LGG for 7 d prior to the colonoscopy, and the adhesion of the bacteria to the colonic mucosa was evaluated by RT-PCR and compared with that of control biopsies from patients who did not consume the formulation. LGG adhesion and TNFα and IL-17 expression were compared between UC patients who consumed a regular or double dose of LGG supplementation prior to colonoscopy. In the experiment, LGG showed consistent adhesion to the distal and proximal colon in normal subjects and UC patients, with a trend towards higher concentrations in the distal colon, and in UC patients, adhesion was similar in biopsies with active and quiescent inflammation. In addition, bioptic samples from UC patients incubated with LGG conditioned media (CM) showed reduced expression of TNFα and IL-17 compared with the corresponding expression in controls ( < 0.05). Incubation with a double dose of LGG increased mucosal adhesion and the anti-inflammatory effects ( < 0.05). In the experiment, LGG was detectable only in the colon of patients who consumed the LGG formulation, and bowel cleansing did not affect LGG adhesion. UC patients who consumed the double LGG dose had increased mucosal concentrations of the bacteria and reduced TNFα and IL-17 expression compared with patients who consumed the regular dose (48% and 40% reduction, respectively, < 0.05). In an organ culture model, LGG showed consistent adhesion and anti-inflammatory effects. Colonization by LGG after consumption for a week was demonstrated in the human colon. Increasing the administered dose increased the adhesion and effectiveness of the bacteria. For the first time, we demonstrated that LGG effectively adheres to the colonic mucosa and exerts anti-inflammatory effects, both and .