Honeybees can provide humans with various bee products, such as pollen, honey, royal jelly, and propolis (Nainu et al. 2021). Honeybees are also important pollinators worldwide (Khalifa et al. 2021), increasing crop yields and maintaining the stability of ecosystems and the diversity of plant communities (Dai et al. 2018). A previous study has shown that 85% of the main crops directly related to food rely on pollination by insects such as honeybees (Klein et al. 2007). The gut microbial composition of honeybees is simpler than that of humans (Kwong and Moran 2016). The honeybee gut harbors a diverse microbial community, among which lactic acid bacteria (LAB) and bifidobacteria are beneficial in the intestine (Ge et al. 2021). On the contrast, some pathogenic bacteria such as
A prebiotic is defined as “a substrate that is selectively utilized by host microorganisms conferring a health benefit” by the International Scientific Association for Probiotics and Prebiotics (ISAPP) (Gibson et al. 2017). Commonly used prebiotics include inulin (INU), fructo-oligosaccharides (FOS), xylo-oligosaccharides (XOS), and isomalto-oligosaccharides (IMO) (Carlson et al. 2017; Poeker et al. 2018; Sorndech et al. 2018; Tandon et al. 2019). Prebiotics can alter the gut microbiota composition and promote host health by accumulating organic acids (Rastall and Gibson 2015). Prebiotics, which mainly favor bifidobacteria and lactobacilli, can be fermented to generate short-chain fatty acids (SCFAs) with colonic bacteria to fight chronic diseases (Tornero-Martínez et al. 2019). A synbiotic is a mixture comprising live microorganisms and substrate(s), selectively utilized by host microorganisms that confer a health benefit on the host (Swanson et al. 2020). Lactic acid bacteria, the most widely used probiotics, antagonize the pathogenic bacteria and influence the gut microbiota of the honeybees (Williams 2010; Audisio et al. 2015; Ramos et al. 2020). These studies highlight the potential of prebiotics and synbiotics modifying the gut microbiota of honeybees and consequently improving host health. However, little is known about the effects of prebiotics and synbiotics on the intestinal microbiota of
Number of
Number of gut microbiota / Log10 (CFU/ml) | Time (h) | Treatment | ||||
---|---|---|---|---|---|---|
GLU | FOS | INU | IMO | XOS | ||
0 | 5.85 ± 0.06Ca | 5.82 ± 0.05Ca | 5.83 ± 0.02Ca | 5.82 ± 0.01Ca | 5.80 ± 0.02Ca | |
6 | 5.63 ± 0.03Db | 5.66 ± 0.16Cab | 5.83 ± 0.13Cab | 5.94 ± 0.19Ca | 5.81 ± 0.15Cab | |
12 | 6.99 ± 0.08Bc | 6.46 ± 0.25Bd | 7.79 ± 0.08Bb | 8.31 ± 0.36Ba | 7.43 ± 0.24Bb | |
24 | 8.15 ± 0.05Ad | 8.41 ± 0.08Ac | 8.85 ± 0.02Ab | 9.10 ± 0.12Aa | 8.52 ± 0.18Ac | |
LAB | 0 | 5.01 ± 0.02Da | 4.99 ± 0.03Ba | 5.00 ± 0.02Da | 5.01 ± 0.05Ca | 4.98 ± 0.02Ca |
6 | 6.03 ± 0.03Cb | 5.06 ± 0.16Bc | 6.10 ± 0.09Cab | 6.34 ± 0.19Ba | 5.21 ± 0.15Cc | |
12 | 7.29 ± 0.08Bc | 5.76 ± 0.25Ad | 8.09 ± 0.08Bab | 8.28 ± 0.33Aa | 7.73 ± 0.24Bb | |
24 | 7.76 ± 0.14Ac | 5.67 ± 0.35Ad | 8.36 ± 0.11Aab | 8.61 ± 0.02Aa | 8.19 ± 0.16Ab |
GLU – glucose; FOS – fructo-oligosaccharides; INU – inulin; IMO – isomalto-oligosaccharides; XOS – xylo-oligosaccharides
A-D – different uppercase letters between treatments using the same prebiotic at the different fermentation timing denote significance (
a-d – different lowercase letters between different treatments at the same time fermentation point denote significance (
The number of LAB in each group of the fermentation broth supplemented with oligosaccharides or glucose increased in a time-dependent manner (Table I). Compared to the GLU group, IMO showed a significant increasing effect on LAB growth at all time points. The LAB number in both INU and XOS groups was higher than those in the GLU group after 12 and 24 h of fermentation. There was no significant difference in the LAB number between IMO and INU groups (
The pH value in the prebiotic fermentation broth of
Time (h) | pH value | ||||
---|---|---|---|---|---|
GLU | FOS | INU | IMO | XOS | |
0 | 6.98 ± 0.03Aa | 7.00 ± 0.04Aa | 6.98 ± 0.06Aa | 7.01 ± 0.02Aa | 6.99 ± 0.03Aa |
6 | 6.89 ± 0.04Ba | 6.91 ± 0.05Ba | 6.89 ± 0.07Aa | 6.89 ± 0.03Ba | 6.90 ± 0.06Ba |
12 | 6.13 ± 0.07Cb | 6.31 ± 0.03Ca | 5.71 ± 0.02Bd | 5.57 ± 0.07Ce | 5.97 ± 0.05Cc |
24 | 5.78 ± 0.07Db | 6.22 ± 0.04Da | 5.59 ± 0.04Cc | 5.48 ± 0.03Dd | 5.65 ± 0.03Dc |
GLU – glucose; FOS – fructo-oligosaccharides; INU – inulin; IMO – isomalto-oligosaccharides; XOS – xylo-oligosaccharides
A-D – different uppercase letters between treatments using the same prebiotic at the different fermentation timing denote significance (
a-d – different lowercase letters between different treatments at the same fermentation point time denote significance (
After 6 or 24 h of fermentation, the use of
The combination of IMO and
Compared to the IMO group, after 6 and 12 h, IMO supplemented with
In this study, the experiment design evaluated
Increasing evidence in both
In the current study,