Showing results of query in dialogflow from php file - php

Question

so I am creating a chatbot using dialogflow. I am writing my code in a php file and I am trying to get data from my database. The connection to the database works and the query returns results that I put in a varialbe called $ppp.I echo my results using a sendMessage function that I defined.The only problem is that I am only able to echo first result of the request it seems like the while loop isn't working or maybe there's a problem with the sendMessage function I don't know what to do.
<?php
header('Content-Type: text/html; charset=utf-8');
date_default_timezone_set("Asia/Bangkok");
$date = date("Y-m-d");
$time = date("H:i:s");
$json = file_get_contents('php://input');
$request = json_decode($json, true);
$input = fopen("log_json.txt", "w") or die("Unable to open file!");
fwrite($input,$json);
fclose($input);
function processMessage($update) {
if($update["queryResult"]["action"] == "ques"){
$bdd= new PDO('mysql:host=localhost;dbname=*****', '*****', '*****', array(
PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8")) ;
$nom= $update["queryResult"]["parameters"]["nom_aliment"];
$info=$update["queryResult"]["parameters"]["Information"];
$quantite=$update["queryResult"]["parameters"]["Quantite"];
$req=$bdd->query("SELECT * FROM TableCiqual");
$req=$bdd->prepare("SELECT * FROM TableCiqual WHERE alim_nom LIKE ? ");
$req->execute(array("%$nom%"));
while($resultat=$req->fetch()){
$variab=$resultat[$info]*$quantite/100;
$ppp =$resultat['alim_nom'].' '.$info.' : '.$variab;
sendMessage(array(
"source" => $update["responseId"],
"fulfillmentText"=>$ppp,
"payload" => array(
"items"=>[
array(
"simpleResponse"=>
array(
"textToSpeech"=>"Bad request"
)
)
],
),
));
//}
}
}
function sendMessage($parameters) {
echo json_encode($parameters);
}
$update_response = file_get_contents("php://input");
$update = json_decode($update_response, true);
if (isset($update["queryResult"]["action"])) {
processMessage($update);
}else{
sendMessage(array(
"source" => $update["responseId"],
"fulfillmentText"=>"Hello from webhook",
"payload" => array(
"items"=>[
array(
"simpleResponse"=>
array(
"textToSpeech"=>"Bad request"
)
)
],
),
));
}
?>