An evaluation of the effects of Lactobacillus ingluviei on body weight, the intestinal microbiome and metabolism in mice.
BACKGROUND
Food can modify the intestinal flora, and Lactobacillus ingluviei has been shown to cause weight gain in chicks and ducks but not in mammals.


METHODS
Female BALB/c mice were divided into a control and two experimental groups and were inoculated either once or twice with L. ingluviei or with PBS. Faecal samples were collected and tested using qPCR in order to detect and quantify Lactobacillus spp., Bacteroidetes spp. and Firmicutes spp. Gene expression was examined in liver and adipose tissue by microarray and qPCR. Metabolic indicators in the plasma were also measured.


RESULTS
Mice that were inoculated with 4 × 10(10) L. ingluviei presented a significant increase in weight gain and liver weight and significant increases in Lactobacillus spp. and Firmicutes DNA copy numbers in their faeces. The mRNA levels of fatty acyl synthase (Fas), sterol regulatory element binding factor 1 (Srebp1c), tumour necrosis factor alpha (Tnf), cytochrome P450 2E1 (Cyp2e1), 3-phosphoinositide-dependent protein kinase-1 (Pdpk1), acyl-Coenzyme A dehydrogenase 11 (Acad11), ATP-binding cassette sub family member G (ABCG2) and DEAD box polypeptide 25 (Ddx25) were significantly elevated in the liver tissues of animals in the experimental group. In gonadal adipose tissue, the expression levels of leptin, peroxisome proliferator-activated receptor γ (Pparg) and Srebp1c were significantly higher in animals from the experimental group, whereas the expression of adiponectin was significantly lower in these animals.


CONCLUSIONS
The inoculation of L. ingluviei in mice resulted in alterations in the intestinal flora, increased weight gain and liver enlargement, accelerated metabolism and increased inflammation.
Unité des Rickettsies, CNRS UMR 6020, IFR 48, Faculté de Médecine, Université de la Méditerranée, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France.
Emmanouil
E
Angelakis
Delphine
D
Bastelica
Amira
A
Ben Amara
Adil
A
El Filali
Anne
A
Dutour
Jean-Louis
JL
Mege
Marie-Christine
MC
Alessi
Didier
D
Raoult
D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D001835:Body Weight; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D008099:Liver / Q000378:metabolism; D008297:Male; D054892:Metagenome; D051379:Mice; D008807:Mice, Inbred BALB C; D009765:Obesity / Q000378:metabolism / Q000503:physiopathology*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D019936:Probiotics / Q000008:administration & dosage / Q000009:adverse effects*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D015430:Weight Gain
D047495:PPAR gamma; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1