Inclusion of limited amounts of extruded legumes plus cereal mixes in normocaloric or obesogenic diets for rats: effects on intestinal microbiota composition

Abstract

BACKGROUND: Differences in the composition of the intestinal microbiota and energetic metabolism between lean and obese populations have been described. Legume consumption has been reported to modulate intestinal microbiota composition. However, to the best of our knowledge, no information can be found in the literature on the effects of consumption of diets containing extruded legume plus cereal mixes on the intestinal microbiota composition of rats. Our purpose was to evaluate the effects on lipids profile (see the accompanying paper) and intestinal microbiota composition (current paper) of incorporating this new food ingredient in normocaloric and obesogenic diets. RESULTS: Intestinal and fecal qPCR-based microbial composition of rats fed the extruded legumes plus cereal mixes differed (P < 0.05) from controls. Obesogenic diets did not affect bacterial counts. However, the inclusion of the extruded mixes reduced (P < 0.05) log 10 counts in some bacterial groups and increased (P < 0.05) counts of Lactobacilli, while others remained unaffected. PCoA at the genus level grouped together Lactobacillus reuteri, Akkermansia miciniphila and species from Parabacteroides, Prevotella, Rikenellaceae, and Lactobacillus with extruded legume plus cereal diets. Feeding on extruded legumes plus cereal mixes was associated with increased mRNA expression of the cytokines IL6 and TNF-⊍ and decreased expression of TLR4. CONCLUSIONS: Our results show that the inclusion in the feed of limited amounts of extruded legumes plus cereal mix, providing a diet that is closer to a normal human one, did modulate the intestinal microbiota composition. Taken together, these results point to the protective, health-promoting properties of extruded legume plus cereal mixes.

Carbohydrates digestibility and faecal microbiota composition in rats fed diets based on raw or fermented Vigna unguiculata seed meal as the only protein source

“…This is apparently contrary to what we found previously with other legumebased diets ( Rubio, Aranda-Olmedo, Contreras, & Góngora, 2020 ), but in that previous work we did not supplement the control diet with any additional fibre sources, except cellulose which is mostly indigestible. In fact, although not strictly comparable, it is interesting to note that variability values for the control casein diet in Rubio et al (2020) were generally lower than those here reported. The animals fed the CM12 control diet had higher faecal proportions of Bacteroides spp.…”

“…The results here reported are very much in line with previous work by our group using other legume seed meals and/or legume seed fractions ( Aranda-Olmedo, Ruiz, Peinado, & Rubio, 2017 ;Rubio et al, 2020 ), and broadly agree with the so-called enterotypes concept introduced by Arumugam in 2011, and with work in children from Europe and rural Africa (for more details see Aranda-Olmedo et al, 2017 andRubio et al, 2020 ). In general terms, as shown in Figs.…”

Inclusion of Limited Amounts of Extruded Legumes Plus Cereal Mixes in Normocaloric or Obesogenic Diets for Rats: Effects on Lipid Profile

“…Finally, bile acid metabolism is known to be modulated by gut microbiota, affecting the biotransformation, reabsorption, and excretion of bile acids by catalysing a range of biochemical reactions [ 61 ]. Nakatani et al [ 62 ] have recently found an elevated cecal and faecal bile acid pool in mice that had consumed mung bean protein, and those changes were linked to dramatic changes in the gut microbiome, such as such as changes in the Firmicutes/Bacteroidetes proportions (see Rubio et al [ 16 ]).…”

“…In this context, new highly palatable [ 14 ] extruded mixes of legumes plus cereals similar to a snack food have been produced [ 15 ]. Two of these extruded mixes have been incorporated in the current work into normocaloric or obesogenic diets for rats to evaluate the effects on lipid profile and intestinal microbiota composition [ 16 ]. Obesogenic diets are those that promote obesity by presenting high caloric contents mainly from a high proportion of carbohydrates, usually simple sugars and/or fats [ 17 ].…”

Dietary Milk or Isolated Legume Proteins Modulate Intestinal Microbiota Composition in Rats

“…Bacterial log 10 number of copies was determined by using quantitative polymerase chain reaction (q-PCR) (iQ5 Cycler, Bio-Rad Laboratories, Alcobendas, Spain). The 16S rRNA gene-targeted primers and polymerase chain reaction (PCR) conditions used in this study were as described previously [ 14 ]. The different microbial groups quantified included Lactobacillus spp., Bifidobacterium spp., Blautia coccoides/Eubacterium rectale group, Clostridium leptum/Ruminococcus spp., Enterobacteriaceae , Escherichia/Shigella , Bacteroides/Prevotella spp., and total bacteria.…”