In vitro simulated digestion and fecal fermentation of polysaccharides from loquat leaves: Dynamic changes in physicochemical properties and impacts on human gut microbiota
Introduction
Loquat (Eriobotrya japonica L.), belongs to the Rosaceae family, which is widely distributed in Southeastern China [1]. The loquat leaves are widely consumed as the main raw materials of tea, functional foods, and Chinese medicine [2]. A growing body of research has illustrated that the extracts of loquat leaves, such as phenolic compounds and polysaccharides, exhibit various biological activities, including hepatoprotective [3], anti-inflammatory [4], anti-diabetic [5], anti-obesity [6], prebiotic [7], and antioxidant effects [8,9]. Meanwhile, the contents of polysaccharides which richly distributed in loquat leaves are ranged from 2.87% to 5.29% [7,9,10]. Rhamnose, galacturonic acid, arabinose, and galactose are considered to be the dominant monosaccharides in polysaccharides from loquat leaves, indicating that the pectic-polysaccharides might exist in loquat leaves [9]. Hence, polysaccharides from loquat leaves (LLP) have the potentiality to be developed into functional foods and functional ingredients for industrial application.
The system of digestive tract has the functions of wriggling and secreting. The digestion and absorption of polysaccharides are carried by this system. Previous studies have revealed that the chemical structure, surface morphology, and antioxidant capacity of polysaccharides are markedly altered after the simulated gastrointestinal digestion. The enzymes, bile salts, and pH during the simulated digestion can influence the physicochemical properties of polysaccharides [11]. However, the indigestible polysaccharides can also be easily found in some plants, such as polysaccharides from Gracilaria lemaneiformis and Lycium barbarum [12,13]. Recently, the study on the fermentable characteristics of indigestible polysaccharides by gut microbes is a prevalent trend. Gut microbes can award numerous health benefits to the host, including pathogen defense, antibiotic resistance, and nutrient absorption. Polysaccharide is a beneficial dietary source which can impact the composition and abundance of gut microbes [14]. Furthermore, numerous studies have demonstrated that the short-chain fatty acids (SCFAs) can be produced from the fermentation of indigestible polysaccharides by human gut microbiota, such as Lactobacillus and Bifidobacterium, which are regarded as health-promoting gut microbiota. Moreover, acetic, propionic, and butyric acids are the major SCFAs produced from the fermentation of indigestible polysaccharides by gut microbiota, which are the important energy source for the epithelial cells of intestinal, and directly regulate metabolic syndromes [13,15]. Dietary polysaccharides seem to possess many health-promoting properties, but it is still unclear about the digestion and absorption mechanism of LLP, as well as the impacts on the regulation of human gut microbiota and the production of SCFAs. Therefore, it is essential to reveal the potential digestion and fermentation mechanism of LLP.
In this study, the dynamic changes of physicochemical characteristics of LLP during the in vitro simulated digestion and subsequent human fecal fermentation were investigated. Furthermore, the impacts of LLP on the composition and abundance of human gut microbiota and the production of SCFAs were analyzed. These findings can provide a scientific basis for promoting polysaccharides from loquat leaves into prebiotics in the functional food industry, and benefical to understand the in vitro digestion and fecal fermentation behaviors of LLP.
Section snippets
Materials and chemicals
The loquat leaves (Eriobotrya japonica cv. Chuannong8) were obtained from Chengdu, Sichuan Province, China. Fructo-oligosaccharides (FOS) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Pancreatin (4000 U/g), Man-Rogosa-Sharpe (MRS) medium, and α-amylase (3700 U/g) were bought from Solarbio (Beijing, China). Pepsin (3000 U/g) was bought from Aladdin (Shanghai, China). Other chemicals which utilized in the present study were of analytical grade.
Preparation of polysaccharides from loquat leaves
Ultrasonic assisted extraction was carried
Dynamic changes of reducing sugar contents
It has been confirmed that the increase of reducing sugar content is generally related to the breakdown of glycosidic linkages in polysaccharides [21]. As shown in Table 1, there was no significant change of the CR of LLP during the salivary digestion, suggesting that LLP was relatively stable under the salivary juice digestion. However, the CR of LLP significantly increased to 0.624 ± 0.045 mg/mL after the stimulated gastric digestion for 6 h, and gradually increased to 1.103 ± 0.005 mg/mL
Conclusion
LLP could be slightly degraded by the simulated digestive system. During in vitro fecal fermentation, the indigestible LLP-I was degraded and consumed by gut microbiota, and the composition and abundance of gut microbiota were regulated. LLP-I could promote the growth of some beneficial bacteria, resulting in the enhancement of production of health-promoting SCFAs. Results from this study suggest that LLP can be developed as a potential prebiotic in functional food industry.
CRediT authorship contribution statement
Ding-Tao Wu, Data curation, Formal analysis, Funding acquisition, Methodology, Supervision, Project administration, Writing – review & editing. Yuan Fu, Data curation, Formal analysis, Investigation, Resources, Software, Roles/Writing – original draft; Huan Guo, Formal analysis, Investigation, Validation; Qin Yuan, Formal analysis, Investigation; Xi-Rui Nie, Formal analysis, Investigation; Sheng-Peng Wang, Resources, Software; Ren-You Gan, Formal analysis, Funding acquisition, Supervision.
Declaration of competing interest
The authors declare that there are no conflicts of interest.
Acknowledgement
This work was supported by the Central Public-interest Scientific Institution Basal Research Fund, CAFS (grant number Y2020XK05), the National Natural Science Foundation of China (grant number 31901690), and the Scientific Research Foundation of Sichuan Agricultural University (grant number 03120321).
References (36)
- et al.
Anti-inflammatory and antinociceptive properties of the leaves of Eriobotrya japonica
J. Ethnopharmacol.
(2011) - et al.
Polysaccharides from loquat (Eriobotrya japonica) leaves: impacts of extraction methods on their physicochemical characteristics and biological activities
Int. J. Biol. Macromol.
(2020) - et al.
Comparison of structural characteristics and bioactivities of polysaccharides from loquat leaves prepared by different drying techniques
Int. J. Biol. Macromol.
(2020) - et al.
Physicochemical characteristics and biological activities of polysaccharides from the leaves of different loquat (Eriobotrya japonica) cultivars
Int. J. Biol. Macromol.
(2019) - et al.
Effect of simulated gastrointestinal digestion in vitro on the antioxidant activity, molecular weight and microstructure of polysaccharides from a tropical sea cucumber (Holothuria leucospilota)
Food Hydrocoll.
(2019) - et al.
In vitro digestibility and prebiotic activities of a sulfated polysaccharide from Gracilaria Lemaneiformis
J. Funct. Foods
(2020) - et al.
In vitro digestion under simulated saliva, gastric and small intestinal conditions and fermentation by human gut microbiota of polysaccharides from the fruits of Lycium barbarum
Int. J. Biol. Macromol.
(2019) - et al.
In vitro fermentation of Gracilaria lemaneiformis sulfated polysaccharides and its Agaro-oligosaccharides by human fecal inocula and its impact on microbiota
Carbohydr. Polym.
(2020) - et al.
Structural characterization and in vitro fermentation of a novel polysaccharide from Sargassum thunbergii and its impact on gut microbiota
Carbohydr. Polym.
(2018) - et al.
Effects of simulated saliva-gastrointestinal digestion on the physicochemical properties and bioactivities of okra polysaccharides
Carbohydr. Polym.
(2020)
Dynamic digestion of tamarind seed polysaccharide: indigestibility in gastrointestinal simulations and gut microbiota changes in vitro
Carbohydr. Polym.
Digestion under saliva, simulated gastric and small intestinal conditions and fermentation in vitro by human intestinal microbiota of polysaccharides from Fuzhuan brick tea
Food Chem.
Influences of different drying methods on the structural characteristics and multiple bioactivities of polysaccharides from okra (Abelmoschus esculentus)
Int. J. Biol. Macromol.
Physicochemical characteristics and antioxidant activities of non-starch polysaccharides from different kiwifruits
Int. J. Biol. Macromol.
In vitro digestibility and prebiotic potential of a novel polysaccharide from Rosa roxburghii Tratt fruit
J. Funct. Foods
Simulated digestion and fermentation in vitro with human gut microbiota of polysaccharides from Coralline pilulifera
LWT Food Sci. Technol.
Structural characterization and in vitro gastrointestinal digestion and fermentation of litchi polysaccharide
Int. J. Biol. Macromol.
Effects of simulated gastrointestinal digestion in vitro on the chemical properties, antioxidant activity, α-amylase and α-glucosidase inhibitory activity of polysaccharides from Inonotus obliquus
Food Res. Int.
Cited by (83)
Studies of peach gum polysaccharide on gut microbiota in vitro fermentation by human feces
2025, Journal of Future FoodsIn vitro digestion properties of Laiyang pear residue polysaccharides and it counteracts DSS-induced gut injury in mice via modulating gut inflammation, gut microbiota and intestinal barrier
2024, International Journal of Biological MacromoleculesIn vivo absorption, in vitro simulated digestion and fecal fermentation properties of polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine and their effects on human gut microbiota
2024, International Journal of Biological MacromoleculesAdsorption, in vitro digestion and human gut microbiota regulation characteristics of three Poria cocos polysaccharides
2024, Food Science and Human WellnessIn vitro digestive properties of Dictyophora indusiata polysaccharide by steam explosion pretreatment methods
2024, International Journal of Biological Macromolecules
- 1
These authors contributed equally to this work.