Small Intestinal Mucosal Cell Proliferation and Bacterial Flora in the Conventionalization of the Germfree Mouse

Abstract

Intestinal mucosal cells, originating in the crypts, migrate up the villi of the small intestine and slough off into the lumen (1, 2). Studies of the kinetics of these events have revealed a differential rate of cellular renewal between the intestinal mucosal cells of germfree animals and those of conventional animals (3, 4). The time for migration of the mucosal cells from the crypt to villus tip is twice as long in the germfree animal (3, 4). The absence of intestinal bacterial flora in the germfree animal may account for this difference in dynamic morphology.Recent advances in intestinal and fecal culturing techniques have provided information about the intestinal bacterial flora under normal and experimental conditions (5-7). The changing patterns of intestinal microorganisms have been followed both in newborn animals (8-11) and after contamination in germfree animals (12).The present study was designed to follow the changes in intestinal cellular renewal and microbial flora as a function of time in going from a germfree system to a conventional one. Experiments involving both gerrafree and conventional animals have utilized conventionalized (formerly germfree) animals as the control subjects; however, the possibility of altering cellular kinetics of the intestinal epithelium and the span necessary for the alteration have not previously been investigated. Materials and MethodsAnimals.--35 male and 35 female CFW mice (Carworth Farms, New City, N. Y.) born and reared under standard germfree conditions were randomly divided into two groups,

The role of gut microbiota in immune homeostasis and autoimmunity

“…A reduced proliferation rate and lower expression of antimicrobial genes of IECs was observed in GF and broad-spectrum antibiotictreated mice. 37,38 These data suggest that the gut microbiota can condition the immunoregulatory roles of IECs by regulating the expression of antimicrobial factors.…”

Measurement of Bioavailable Energy in Poultry Feedingstuffs: A Review

“…The microflora of the alimentary canal had no effect on the true digestibilities of proteins but were able to modify the route of excretion of undigested nitrogenous compounds reaching the lower gut (Salter and Coates 1971;Salter and Fulford 1974;Salter et al 1974). However, according to Erbersdobler and Riedel (1912) Work with mice has shown that intestinal microflora alter cell renewal rates in the ileum (Abrams et al 1963), duodenal crypts (Lesher et al 1964) and small intestine (Khoury et al 1969 Yoshida et al (1965), Yoshida and Morimoto (1966,1970) and Squibb (1971 (1961) found the AME values of oats to increase with bushel weight; this was confirmed by Sibbald and Slinger (1963a), Sibbald and Price (1976a) but not by Salo (1978) whose AME values were calculated from chemical composition. The TME values of oats were related to bulk density (Sibbald and Price 1977a) as were ADE values measured with mice (Christison and Bell 1975 (Hochstetler and Scott 1975 Carpenter and Clegg (1956), Bolton (1962b) and Sibbald et al.…”

Effect of various modifications in the diet on ileal epithelium renewal in germ-free and conventional rats

“…(Stragand and Hagemann, 1977 (Bayle, 1969 ;Coates et ol., 1969 ;Hiller and Schoen, 1971 Rolls et al,1975 ;mouse : Abrams et al,1963 ;Lesher et al,1964 ;Khoury et al, 1969 ;Ranken, Wilson and Bealmer, 1971 ;Mastromarino and Wilson, 1976 ;rat : Guenet et al, 1970 ;Galjaard et at., 1972 ;Meslin et al, 1974) or partial (Meslin, Sac- …”