Table 5.

Examples of clinical trials regarding the effect of probiotics on SCFAs production by human intestinal microbiota.

Subjects	Probiotic	Time of Administration	Main Outcome	Ref.
Colorectal Cancer (CRC)
30 patients (10 CRC patients and 20 healthy subjects)	Lactobacillus gasseri OLL271 6: LG21	12 weeks	↑ number of Lactobacillus spp. ↓ number of Clostridium perfringens in intestinal population; ↑ concentration isobutyric acid in feces and natural killer (NK) cell activity; ↓ pH and the synthesis of fecal putrefaction products.	[103]
17 healthy subjects (aged 45 to 75 years)	Bifidobacterium lactis LAFTI B94	4 weeks	↑ number of Bifidobacterium lactis in intestinal population; no changes in the pH, the SFCA fecal concentration, the serum hs-CRP and cytokines and also the crypt proliferation and cell height.	[104]
Obesity
40 children 7–10 years (19 normal weight and 21overweight children)	Lactobacillus casei Shirota	2 phases (each lasted for 4 weeks with a 4-week wash-out period between phases)	↑ number of Lactobacillus spp. and Bifidobacterium spp.; ↑ the total SCFAs and propionic acid contents in normal weight and overweight children.	[2]
34 children 8.5–10.8 years (22 normal weight and 12 overweight children)	Lactobacillus casei Shirota	6 months	↓ weight; improving the lipid metabolism in children with obesity; ↑ number of Bifidobacterium spp. and the acetic acid concentration in the feces.	[24]
Type 2 Diabetes
50 volunteers with T2D	Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis BB-12	6 weeks	the proportion of C3:C2:C4 acids, taking into account the mean values, was also similar: 10:8:1 in the control group and 14:10:1 in the probiotic group, improving glycemic control.	[105]
Gastrointestinal Disorders
22 children with shigellosis and 11 children with salmonellosis (mean age–5.3 years)	Lactobacillus rhamnosus GG (ATCC 53103)	In three portions per day for 10 days compared to treatment with an antibacterial drug (TMP-SMX or Polymyxin) for 5 days.	acetic, propionic and iso-valeric acid were significantly higher in shigellosis than in salmonellosis. ↑ concentration of propionic acid by the 5th day of treatment; difference in iso-caproic acid in the 10th day samples: it was not found in any child who had received probiotic but was present in half of the samples from the group treated solely with antibacterial drug.	[106]
Autism Spectrum Disorders
97 children (58 children with ASD–two groups: A-Probiotic, A-No-Probiotic and 39 healthy children) (2.5–18 years)	No information		↓ level of acetate, propionate and valerate and total SCFAs in children with autism; the imbalance of gut microbiota in children with autism.	[107]
Atopic Dermatitis
19 AD children and 18 healthy individuals (0–6 years)	Bifidobacterium breve BR03, Lactobacillus salivarius LS01	20 days	an alteration in AD microbiome composition with the depletion or absence of some species; ↓ SCFAs producing bacteria.	[108]