# A Review of the Relationship between Gut Microbiome and Obesity
## 5 Effect of Diet or Dietary Components on the Gut Microbiota  
As a substrate for microbial metabolism, diet plays a significant role in widening the individual microbiome, modulated positively or negatively by different diets and dietary components [2]. Western diets (low in fibre, vegetables, fruits; high in saturated fat, sugar and animal protein) have consequences beyond metabolic aspects (hyperinsu-linemia, insulin resistance, dyslipidemia, overstimulation of sympathetic nervous system and renin-angiotensin system, oxidative stress), in addition to dysbiosis, intestinal barrier dysfunction, increased intestinal permeability, and leakage of toxic bacterial metabolites into the blood circulation, may contribute significantly to the development of low-grade systemic inflammation [34; 47]. However, these dietary patterns--high fat, carbohydrate and animal protein, low fibre intake--induce changes in the gut microbiota in different ways.  
The effects of certain diets or dietary components on the gut microbiota and host are shown in Table 2.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Diet or Dietary Pattern** & **Impact on Microbiome** & **Impact on Host** & **Reference** \\ \hline \multirow{8}{*}{Vegan/vegatarian diet} & \(\uparrow\)_Prevotella_ & \multirow{8}{*}{Vegan/vegatarian diet} & \multirow{8}{*}{\(\uparrow\)_E. rectale_} & \multirow{8}{*}{\(\downarrow\)Visceral fat} \\  & \(\uparrow\)_Roseburia_ & & \\  & \(\uparrow\)_Ruminococcus_ & & \\  & \(\uparrow\)_Bilidobacterium_ & & \\  & \(\downarrow\)_E. coli_ & & \(\downarrow\)Body mass \\  & \(\downarrow\)_Firmicutes_ & & \(\downarrow\)Inflammation & [48; 49; 50; 51; 52] \\  & \(\uparrow\)_E. rectale_ & & Promote gut barrier integrity via & \\  & \(\uparrow\)_E.transuitzii_ & & anti-tumorigenis & \\  & \(\uparrow\)_Anarostiges_ & & \\  & \(\uparrow\)_Streptococcus_ & & \\  & \(\uparrow\)_Odoribacter_ & & \\  & \(\uparrow\)_Clastridium sensu stricto_ & & \\ \hline \multirow{4}{*}{Vegan diet with low fat} & \(\uparrow\)_Bacteroides_ & \(\downarrow\)Body mass & \\  & \(\uparrow\)_C.clastridiformone_ & \(\downarrow\)Body fat & \\  & \(\uparrow\)_Facetium pneumsitzii_ & \(\downarrow\)Visceral fat & [53] \\  & \(\downarrow\)_Firmicutes_ & \(\uparrow\)Insulin sensitivity & \\ \hline \multirow{8}{*}{Dietary fibre} & \(\uparrow\)_Prevotella_ & \multirow{8}{*}{\(\uparrow\)_Lactobacillus_} & \multirow{8}{*}{\(\uparrow\)SCFA synthesis} \\  & \(\uparrow\)_Ruminococcus bromii_ & \(\downarrow\)Body mass & [49] \\  & \(\downarrow\)_Firmicutes_ & & \\ \hline \multirow{8}{*}{Inulin} & \(\uparrow\)_Actinobacteria_ & \multirow{8}{*}{\(\downarrow\)_Lostridia_} & \multirow{8}{*}{\(\downarrow\)B. obeum_} & \multirow{8}{*}{\(\uparrow\)Insulin sensitivity} \\  & \(\downarrow\)_B. lutti_ & & \\ \(\downarrow\)_B. facis_ & \(\downarrow\)Body weight & \\ \(\downarrow\)_R. facis_ & \(\downarrow\)BMH & [54; 55] \\  & \(\downarrow\)_Cscillincter_ & \(\downarrow\)Fat mass & \\ \(\uparrow\)_Bifidobacterium_ & \(\downarrow\)Visceral fat & \\ \(\uparrow\)_Catenibacterium_ & & \\ \(\downarrow\)_Desulfovibrio_ & & \\ \(\downarrow\)_Roseburia_ & & \\ \hline \end{tabular}
\end{table}
Table 2: Effect of diet and dietary components on the gut microbiome and host (\(\uparrow\): increased; \(\downarrow\): decreased).