Molecular weight-engineered lentinan fractions as prebiotic modulators: Steering gut microbiota for precision obesity intervention.

Three molecular weight fractions of water-soluble lentinan (WSL) were successfully derived from Lentinula edodes with distinct molecular weights.

• WSL-40 had a molecular weight of 2.19 × 10^6 Da
• WSL-60 had a molecular weight of 2.96 × 10^5 Da
• WSL-80 had a molecular weight of 1.70 × 10^4 Da
• Fractions were derived from Lentinula edodes cultivated in Zhejiang
• Fractions were investigated using an in vitro fermentation model

WSL-80 reached total sugar glycolysis equilibrium the earliest and produced the maximal butyric acid among the fractions in healthy microbiota.

• WSL-80 is the lowest molecular weight fraction at 1.70 × 10^4 Da
• Maximal butyric acid production was observed with WSL-80 in healthy microbiota
• These effects were characterized as Mw-dependent regulation
• Results were observed using an in vitro fermentation model with healthy individual microbiota

WSL-80 specifically promoted the growth of Parabacteroides in healthy microbiota.

• The effect was statistically significant (p < 0.05)
• This promotion was specific to WSL-80, the lowest molecular weight fraction
• This was observed in the healthy microbiota fermentation model
• WSL demonstrated diet-induced obesity prevention potential through this Mw-dependent regulation

In obese microbiota, WSL fractions alleviated dysbiosis and enhanced proliferation of beneficial genera with Mw-gradient-dependent effects.

• A progressive reduction in the Firmicutes/Bacteroidetes ratio was observed as Mw decreased
• All three WSL fractions demonstrated effects on obese microbiota
• The effects were characterized as showing an 'Mw-gradient-dependent' pattern
• Results were obtained using an in vitro fermentation model with obese individual microbiota

WSL-80 was associated with higher abundances of Phascolarctobacterium, Klebsiella, and Parabacteroides in obese microbiota.

• WSL-80 is the lowest molecular weight fraction (1.70 × 10^4 Da)
• Three distinct genera showed higher abundance with WSL-80 treatment in obese microbiota
• These effects were observed in the in vitro fermentation model using obese individual microbiota
• Parabacteroides was promoted by WSL-80 in both healthy and obese microbiota

Elevated Bacteroides abundance was specifically noted with WSL-60 and WSL-80 fractions in obese microbiota.

• Bacteroides elevation was observed with both medium (WSL-60, 2.96 × 10^5 Da) and low (WSL-80, 1.70 × 10^4 Da) molecular weight fractions
• This effect was not reported for the highest molecular weight fraction WSL-40
• Results were from the in vitro fermentation model with obese microbiota

Maximal Weissella abundance was observed with WSL-40, the highest molecular weight fraction, in obese microbiota.

• WSL-40 has the highest molecular weight at 2.19 × 10^6 Da
• Weissella promotion appeared specific to the highest molecular weight fraction
• This contrasts with other beneficial genera that were more promoted by lower Mw fractions
• Results suggest different molecular weight fractions selectively promote different beneficial bacterial genera

Lentinan molecular weight gradient functions as a directional regulator of functional microbiota composition.

• Different Mw fractions selectively promoted distinct microbial genera in both healthy and obese microbiota
• The study establishes a theoretical basis for precision nutrition interventions against obesity
• The Mw-gradient effects were demonstrated across both healthy and obese microbiota contexts
• Authors describe this as establishing 'lentinan's Mw gradient as a directional regulator of functional microbiota'