## 4 Discussion  
The present study shows that daily consumption of a combination of elderberry and reishi extracts during the winter season is effective in reducing the duration and severity of respiratory \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **Control Group** & **Extract Group** \\ \hline Nausea IR (SD) a  & 0.100 (0.057) & 0.166 (0.074) \\ Lack of appetite IR (SD) a  & 0.666 (0.149) & 0.633 (0.145) \\ Sleeping disturbance IR (SD) a  & 0.899 (0.325) & 0.372 (0.152) * \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Safety parameters. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Control Group** & **Extract Group** & **IR Ratio (95\% CI)** & **IR Decrease, \%** & \(p\)**-Value d  \\  & **IR (SD)** & **IR (SD)** & **IR (SD)** & **IR (SD)** & **IR (SD)** \\ \hline Cough & 0.558 (0.202) & 0.552 (0.177) & 0.989 (0.495–1.976) & 1.1 & 0.976 \\ Nasal congestion & 0.478 (0.200) & 0.357 (0.141) & 0.747 (0.334–1.6719) & 25.3 & 0.478 \\ Sone throat & 0.356 (0.211) & 0.108 (0.073) & 0.302 (0.095–0.963) & 69.8 & 0.043 \\ Fever & 0.244 (0.112) & 0.128 (0.717) & 0.528 (0.52–1.834) & 47.2 & 0.315 \\ Headache & 0.128 (0.937) & 0.102 (0.070) & 0.798 (0.266–2.396) & 21.2 & 0.688 \\ Muscle/Bone Pain & 0.146 (0.92) & 0.138 (0.794) & 0.941 (0.327–2.713) & 5.9 & 0.911 \\ Tiredness/Malaise & 0.180 (0.101) & 0.342 (0.155) & 1.897 (0.755–4.770) & \(-\)89.7 & 0.173 \\ Local Respiratory & 1.466 (0.352) & 1.031 (0.239) & 0.703 (0.440–1.124) & 29.7 & 0.141 \\ Systemic Symptoms b  & 0.754 (0.233) & 0.656 (1.189) & 0.870 (0.500–1.511) & 23 & 0.62 \\ Total Symptoms c  & 2.185 (0.410) & 1.808 (0.316) & 0.828 (0.584–1.174) & 27.2 & 0.289 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Incidence of symptoms related to respiratory infections. infections in elderly people. Several clinical studies have shown the beneficial immunological effect of elderberry [12; 13] and reishi [24], but to our knowledge, this is the first study that evaluated the combined effect of both extracts on the incidence, severity, and duration of respiratory infections in older adults, a population group at increased risk of this type of infection and a worse prognosis of the disease [5]. Elderberry (_Sambucus nigra_ L fruit) has been indicated in several clinical trials to relieve the symptoms of the common cold and influenza when ingested at the onset of infection in children and adults [21; 25; 26; 27]. Additionally, the effect of elderberry has been tested for prevention of respiratory symptoms in situations of high risk of infection, such as intercontinental flights, showing a reduction in the duration and severity of common cold events the travelers developed [28]. The therapeutic effects of elderberry have been attributed to its content of bioactive compounds, such as anthocyanins and other polyphenols, through several mechanisms [29; 30]. First, elderberry extract has been reported to enhance the immune response by increasing both inflammatory and anti-inflammatory cytokines [31; 32]. Second, it was observed that elderberry preparations exert antiviral activity, specifically against human influenza (H1N1) virus. It has been shown that several elderberry compounds directly bind the H1N1 virus particles, resulting in the inability of the particles to enter host cells and in a decreased viral load and spread [33; 34]. Regarding the reishi (_Ganoderma lucidum_), it has been observed in vitro and in animal studies that the triterpens contained in the reishi exert anti-influenza activity by neuraminidase inhibition [35; 36]. Moreover, a recent clinical study reported that a yogurt enriched with \(\beta\)-glucans from reishi increased the absolute count of peripheral blood total lymphocytes (CD3\({}^{+}\), CD4\({}^{+}\), and CD8\({}^{+}\) T cells) compared to a nonenriched yogurt in a group of healthy children [24]. Therefore, the results achieved in this randomized clinical trial could be related to the observed immunomodulatory and antiviral activities of elderberry and reishi.